diff --git a/tests/alchemy/test_filters.py b/tests/alchemy/test_filters.py
index 16737ae67fa..8810ca30551 100644
--- a/tests/alchemy/test_filters.py
+++ b/tests/alchemy/test_filters.py
@@ -14,10 +14,10 @@
 from pymatgen.alchemy.transmuters import StandardTransmuter
 from pymatgen.analysis.structure_matcher import StructureMatcher
 from pymatgen.core import Lattice, Species, Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 
-class TestContainsSpecieFilter(PymatgenTest):
+class TestContainsSpecieFilter:
     def test_filtering(self):
         coords = [[0, 0, 0], [0.75, 0.75, 0.75], [0.5, 0.5, 0.5], [0.25, 0.25, 0.25]]
         lattice = Lattice([[3.0, 0.0, 0.0], [1.0, 3.0, 0], [0, -2.0, 3.0]])
@@ -52,7 +52,7 @@ def test_as_from_dict(self):
         assert isinstance(ContainsSpecieFilter.from_dict(dct), ContainsSpecieFilter)
 
 
-class TestSpecieProximityFilter(PymatgenTest):
+class TestSpecieProximityFilter:
     def test_filter(self):
         struct = self.get_structure("Li10GeP2S12")
         sf = SpecieProximityFilter({"Li": 1})
diff --git a/tests/alchemy/test_materials.py b/tests/alchemy/test_materials.py
index 25b8cc74ad2..2569b7ec46c 100644
--- a/tests/alchemy/test_materials.py
+++ b/tests/alchemy/test_materials.py
@@ -21,7 +21,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/alchemy"
 
 
-class TestTransformedStructure(PymatgenTest):
+class TestTransformedStructure:
     def setUp(self):
         structure = PymatgenTest.get_structure("LiFePO4")
         self.structure = structure
diff --git a/tests/alchemy/test_transmuters.py b/tests/alchemy/test_transmuters.py
index 653a98c5326..17cabc9d930 100644
--- a/tests/alchemy/test_transmuters.py
+++ b/tests/alchemy/test_transmuters.py
@@ -8,10 +8,10 @@
     RemoveSpeciesTransformation,
     SubstitutionTransformation,
 )
-from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR
 
 
-class TestCifTransmuter(PymatgenTest):
+class TestCifTransmuter:
     def test_init(self):
         trafos = [SubstitutionTransformation({"Fe": "Mn", "Fe2+": "Mn2+"})]
         tsc = CifTransmuter.from_filenames([f"{TEST_FILES_DIR}/cif/MultiStructure.cif"], trafos)
@@ -22,7 +22,7 @@ def test_init(self):
             assert expected == els
 
 
-class TestPoscarTransmuter(PymatgenTest):
+class TestPoscarTransmuter:
     def test_init(self):
         trafos = [SubstitutionTransformation({"Fe": "Mn"})]
         tsc = PoscarTransmuter.from_filenames([f"{VASP_IN_DIR}/POSCAR", f"{VASP_IN_DIR}/POSCAR"], trafos)
diff --git a/tests/analysis/chemenv/connectivity/test_connected_components.py b/tests/analysis/chemenv/connectivity/test_connected_components.py
index fc9e561c57e..311f60381fa 100644
--- a/tests/analysis/chemenv/connectivity/test_connected_components.py
+++ b/tests/analysis/chemenv/connectivity/test_connected_components.py
@@ -20,12 +20,12 @@
 from pymatgen.core.lattice import Lattice
 from pymatgen.core.sites import PeriodicSite
 from pymatgen.core.structure import Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "waroquiers"
 
 
-class TestConnectedComponent(PymatgenTest):
+class TestConnectedComponent:
     def test_init(self):
         # Generic connected component not using EnvironmentNodes
         # (as_dict won't work on such a ConnectedComponent instance)
diff --git a/tests/analysis/chemenv/connectivity/test_environment_nodes.py b/tests/analysis/chemenv/connectivity/test_environment_nodes.py
index 60af01acff7..c009a735c81 100644
--- a/tests/analysis/chemenv/connectivity/test_environment_nodes.py
+++ b/tests/analysis/chemenv/connectivity/test_environment_nodes.py
@@ -3,7 +3,6 @@
 import json
 
 from pymatgen.analysis.chemenv.connectivity.environment_nodes import EnvironmentNode
-from pymatgen.util.testing import PymatgenTest
 
 try:
     import bson
@@ -13,7 +12,7 @@
 __author__ = "waroquiers"
 
 
-class TestEnvironmentNodes(PymatgenTest):
+class TestEnvironmentNodes:
     def test_equal(self):
         struct = self.get_structure("SiO2")
         en = EnvironmentNode(central_site=struct[0], i_central_site=0, ce_symbol="T:4")
diff --git a/tests/analysis/chemenv/connectivity/test_structure_connectivity.py b/tests/analysis/chemenv/connectivity/test_structure_connectivity.py
index 37f8da4b98a..bb0452bb747 100644
--- a/tests/analysis/chemenv/connectivity/test_structure_connectivity.py
+++ b/tests/analysis/chemenv/connectivity/test_structure_connectivity.py
@@ -9,12 +9,12 @@
     LightStructureEnvironments,
     StructureEnvironments,
 )
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "waroquiers"
 
 
-class TestStructureConnectivity(PymatgenTest):
+class TestStructureConnectivity:
     def test_serialization(self):
         BaTiO3_se_fpath = f"{TEST_FILES_DIR}/analysis/chemenv/structure_environments/se_mp-5020.json"
         with open(BaTiO3_se_fpath) as file:
diff --git a/tests/analysis/chemenv/coordination_environments/test_chemenv_strategies.py b/tests/analysis/chemenv/coordination_environments/test_chemenv_strategies.py
index 64516b22c41..7c83da588b8 100644
--- a/tests/analysis/chemenv/coordination_environments/test_chemenv_strategies.py
+++ b/tests/analysis/chemenv/coordination_environments/test_chemenv_strategies.py
@@ -10,12 +10,11 @@
     DistanceCutoffFloat,
     SimplestChemenvStrategy,
 )
-from pymatgen.util.testing import PymatgenTest
 
 __author__ = "waroquiers"
 
 
-class TestStrategyOptions(PymatgenTest):
+class TestStrategyOptions:
     def test_options(self):
         # DistanceCutoffFloat
         with pytest.raises(ValueError, match=r"Distance cutoff should be between 1 and \+infinity"):
diff --git a/tests/analysis/chemenv/coordination_environments/test_coordination_geometries.py b/tests/analysis/chemenv/coordination_environments/test_coordination_geometries.py
index 18fc1675835..30d54b9657b 100644
--- a/tests/analysis/chemenv/coordination_environments/test_coordination_geometries.py
+++ b/tests/analysis/chemenv/coordination_environments/test_coordination_geometries.py
@@ -11,7 +11,6 @@
     ExplicitPermutationsAlgorithm,
     SeparationPlane,
 )
-from pymatgen.util.testing import PymatgenTest
 
 __author__ = "waroquiers"
 
@@ -23,7 +22,7 @@ def __init__(self, coords):
         self.coords = coords
 
 
-class TestCoordinationGeometries(PymatgenTest):
+class TestCoordinationGeometries:
     def test_algorithms(self):
         expl_algo = ExplicitPermutationsAlgorithm(permutations=[[0, 1, 2], [1, 2, 3]])
         expl_algo2 = ExplicitPermutationsAlgorithm.from_dict(expl_algo.as_dict())
diff --git a/tests/analysis/chemenv/coordination_environments/test_coordination_geometry_finder.py b/tests/analysis/chemenv/coordination_environments/test_coordination_geometry_finder.py
index 01aedf2d245..f780d439cf7 100644
--- a/tests/analysis/chemenv/coordination_environments/test_coordination_geometry_finder.py
+++ b/tests/analysis/chemenv/coordination_environments/test_coordination_geometry_finder.py
@@ -19,14 +19,14 @@
     symmetry_measure,
 )
 from pymatgen.core.structure import Lattice, Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "waroquiers"
 
 json_dir = f"{TEST_FILES_DIR}/analysis/chemenv/json"
 
 
-class TestCoordinationGeometryFinder(PymatgenTest):
+class TestCoordinationGeometryFinder:
     def setUp(self):
         self.lgf = LocalGeometryFinder()
         self.lgf.setup_parameters(
diff --git a/tests/analysis/chemenv/coordination_environments/test_read_write.py b/tests/analysis/chemenv/coordination_environments/test_read_write.py
index 640770fccad..c120b333953 100644
--- a/tests/analysis/chemenv/coordination_environments/test_read_write.py
+++ b/tests/analysis/chemenv/coordination_environments/test_read_write.py
@@ -22,7 +22,7 @@
 )
 from pymatgen.analysis.chemenv.coordination_environments.voronoi import DetailedVoronoiContainer
 from pymatgen.core.structure import Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "waroquiers"
 
@@ -30,7 +30,7 @@
 struct_env_dir = f"{TEST_FILES_DIR}/analysis/chemenv/structure_environments"
 
 
-class TestReadWriteChemenv(PymatgenTest):
+class TestReadWriteChemenv:
     @classmethod
     def setUpClass(cls):
         cls.lgf = LocalGeometryFinder()
diff --git a/tests/analysis/chemenv/coordination_environments/test_structure_environments.py b/tests/analysis/chemenv/coordination_environments/test_structure_environments.py
index 3f8bde41636..4128b3e0265 100644
--- a/tests/analysis/chemenv/coordination_environments/test_structure_environments.py
+++ b/tests/analysis/chemenv/coordination_environments/test_structure_environments.py
@@ -17,14 +17,14 @@
     StructureEnvironments,
 )
 from pymatgen.core import Species, Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "waroquiers"
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/chemenv/structure_environments"
 
 
-class TestStructureEnvironments(PymatgenTest):
+class TestStructureEnvironments:
     def test_structure_environments(self):
         with open(f"{TEST_DIR}/se_mp-7000.json") as file:
             dct = json.load(file)
diff --git a/tests/analysis/chemenv/coordination_environments/test_voronoi.py b/tests/analysis/chemenv/coordination_environments/test_voronoi.py
index 492cc00df36..6e5a2f10779 100644
--- a/tests/analysis/chemenv/coordination_environments/test_voronoi.py
+++ b/tests/analysis/chemenv/coordination_environments/test_voronoi.py
@@ -5,14 +5,14 @@
 from pymatgen.analysis.chemenv.coordination_environments.voronoi import DetailedVoronoiContainer
 from pymatgen.core.lattice import Lattice
 from pymatgen.core.structure import Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "waroquiers"
 
 img_files_dir = f"{TEST_FILES_DIR}/analysis/chemenv/images"
 
 
-class TestVoronoiContainer(PymatgenTest):
+class TestVoronoiContainer:
     def test_voronoi(self):
         # Define a cubic lattice and a list of species (to be used for the fake structures)
         cubic_lattice = Lattice.cubic(10)
diff --git a/tests/analysis/chemenv/coordination_environments/test_weights.py b/tests/analysis/chemenv/coordination_environments/test_weights.py
index 6a5b2ffe50a..56cffa85a00 100644
--- a/tests/analysis/chemenv/coordination_environments/test_weights.py
+++ b/tests/analysis/chemenv/coordination_environments/test_weights.py
@@ -16,7 +16,7 @@
     SelfCSMNbSetWeight,
 )
 from pymatgen.analysis.chemenv.coordination_environments.structure_environments import StructureEnvironments
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "waroquiers"
 
@@ -39,7 +39,7 @@ class DummyVoronoiContainer:
     pass
 
 
-class StrategyWeights(PymatgenTest):
+class StrategyWeights:
     def test_angle_weight(self):
         fake_nb_set = FakeNbSet()
         dummy_se = DummyStructureEnvironments()
diff --git a/tests/analysis/chemenv/utils/test_chemenv_config.py b/tests/analysis/chemenv/utils/test_chemenv_config.py
index bea8a66770f..3d495f2467f 100644
--- a/tests/analysis/chemenv/utils/test_chemenv_config.py
+++ b/tests/analysis/chemenv/utils/test_chemenv_config.py
@@ -2,14 +2,14 @@
 
 from pymatgen.analysis.chemenv.utils.chemenv_config import ChemEnvConfig
 from pymatgen.core import SETTINGS
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "waroquiers"
 
 config_file_dir = f"{TEST_FILES_DIR}/analysis/chemenv/config"
 
 
-class TestChemenvConfig(PymatgenTest):
+class TestChemenvConfig:
     def test_chemenv_config(self):
         config = ChemEnvConfig()
 
diff --git a/tests/analysis/chemenv/utils/test_coordination_geometry_utils.py b/tests/analysis/chemenv/utils/test_coordination_geometry_utils.py
index d7cbc5b7f19..2439885c09d 100644
--- a/tests/analysis/chemenv/utils/test_coordination_geometry_utils.py
+++ b/tests/analysis/chemenv/utils/test_coordination_geometry_utils.py
@@ -7,12 +7,11 @@
 from pytest import approx
 
 from pymatgen.analysis.chemenv.utils.coordination_geometry_utils import Plane
-from pymatgen.util.testing import PymatgenTest
 
 __author__ = "David Waroquiers"
 
 
-class TestPlanesUtils(PymatgenTest):
+class TestPlanesUtils:
     def setUp(self):
         # Test of plane 4x + 2y - 4z + 3 = 0 (used in most test cases)
         self.expected_coefficients = np.array([4, 2, -4, 3], float)
diff --git a/tests/analysis/chemenv/utils/test_graph_utils.py b/tests/analysis/chemenv/utils/test_graph_utils.py
index b5f32fe7e94..a936a7a5d26 100644
--- a/tests/analysis/chemenv/utils/test_graph_utils.py
+++ b/tests/analysis/chemenv/utils/test_graph_utils.py
@@ -5,7 +5,6 @@
 
 from pymatgen.analysis.chemenv.connectivity.environment_nodes import EnvironmentNode
 from pymatgen.analysis.chemenv.utils.graph_utils import MultiGraphCycle, SimpleGraphCycle, get_delta
-from pymatgen.util.testing import PymatgenTest
 
 __author__ = "waroquiers"
 
@@ -68,7 +67,7 @@ def __lt__(self, other):
         return self.isite % 2 < other.isite % 2
 
 
-class TestGraphUtils(PymatgenTest):
+class TestGraphUtils:
     def test_get_delta(self):
         n1 = FakeNode(3)
         n2 = FakeNode(7)
@@ -664,7 +663,7 @@ def test_multigraph_cycle(self):
             assert mgc.edge_indices == edges_ref, f"Edges not equal for inodes = ({str_nodes})"
 
 
-class TestEnvironmentNodesGraphUtils(PymatgenTest):
+class TestEnvironmentNodesGraphUtils:
     def test_cycle(self):
         e1 = EnvironmentNode(central_site="Si", i_central_site=0, ce_symbol="T:4")
         e2 = EnvironmentNode(central_site="Si", i_central_site=3, ce_symbol="T:4")
diff --git a/tests/analysis/chemenv/utils/test_math_utils.py b/tests/analysis/chemenv/utils/test_math_utils.py
index d3583a24851..90e09e38d09 100644
--- a/tests/analysis/chemenv/utils/test_math_utils.py
+++ b/tests/analysis/chemenv/utils/test_math_utils.py
@@ -16,12 +16,11 @@
     smootherstep,
     smoothstep,
 )
-from pymatgen.util.testing import PymatgenTest
 
 __author__ = "waroquiers"
 
 
-class TestMathUtils(PymatgenTest):
+class TestMathUtils:
     def test_list_cartesian_product(self):
         list_of_lists = [[0, 1], [2, 5, 4], [5]]
         assert _cartesian_product(lists=list_of_lists) == [
diff --git a/tests/analysis/diffraction/test_neutron.py b/tests/analysis/diffraction/test_neutron.py
index 4de897d85d6..0e7ced4628d 100644
--- a/tests/analysis/diffraction/test_neutron.py
+++ b/tests/analysis/diffraction/test_neutron.py
@@ -6,7 +6,6 @@
 from pymatgen.analysis.diffraction.neutron import NDCalculator
 from pymatgen.core.lattice import Lattice
 from pymatgen.core.structure import Structure
-from pymatgen.util.testing import PymatgenTest
 
 """
 These calculated values were verified with VESTA and FullProf.
@@ -20,7 +19,7 @@
 __date__ = "4/19/18"
 
 
-class TestNDCalculator(PymatgenTest):
+class TestNDCalculator:
     def test_get_pattern(self):
         struct = self.get_structure("CsCl")
         c = NDCalculator(wavelength=1.54184)  # CuKa radiation
diff --git a/tests/analysis/diffraction/test_tem.py b/tests/analysis/diffraction/test_tem.py
index c8cfee3b1d5..e8dee624399 100644
--- a/tests/analysis/diffraction/test_tem.py
+++ b/tests/analysis/diffraction/test_tem.py
@@ -11,7 +11,6 @@
 from pymatgen.analysis.diffraction.tem import TEMCalculator
 from pymatgen.core.lattice import Lattice
 from pymatgen.core.structure import Structure
-from pymatgen.util.testing import PymatgenTest
 
 __author__ = "Frank Wan, Jason Liang"
 __copyright__ = "Copyright 2019, The Materials Project"
@@ -21,7 +20,7 @@
 __date__ = "2/20/20"
 
 
-class TestTEMCalculator(PymatgenTest):
+class TestTEMCalculator:
     def test_wavelength_rel(self):
         # Test that the relativistic wavelength formula (for 200 kV electron beam) is correct
         tem_calc = TEMCalculator()
diff --git a/tests/analysis/diffraction/test_xrd.py b/tests/analysis/diffraction/test_xrd.py
index 997c43de42b..4a40a24577e 100644
--- a/tests/analysis/diffraction/test_xrd.py
+++ b/tests/analysis/diffraction/test_xrd.py
@@ -6,7 +6,6 @@
 from pymatgen.analysis.diffraction.xrd import XRDCalculator
 from pymatgen.core.lattice import Lattice
 from pymatgen.core.structure import Structure
-from pymatgen.util.testing import PymatgenTest
 
 __author__ = "Shyue Ping Ong"
 __copyright__ = "Copyright 2012, The Materials Project"
@@ -16,7 +15,7 @@
 __date__ = "5/22/14"
 
 
-class TestXRDCalculator(PymatgenTest):
+class TestXRDCalculator:
     def test_type_wavelength(self):
         """Test TypeError is raised if wavelength is unaccepted type."""
         wavelength = [1.78, 2.78]  # just a list
diff --git a/tests/analysis/elasticity/test_elastic.py b/tests/analysis/elasticity/test_elastic.py
index 699f97d4061..7c6c39b11d0 100644
--- a/tests/analysis/elasticity/test_elastic.py
+++ b/tests/analysis/elasticity/test_elastic.py
@@ -27,12 +27,12 @@
 from pymatgen.core.structure import Structure
 from pymatgen.core.tensors import Tensor
 from pymatgen.core.units import FloatWithUnit
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/elasticity"
 
 
-class TestElasticTensor(PymatgenTest):
+class TestElasticTensor:
     def setUp(self):
         self.voigt_1 = [
             [59.33, 28.08, 28.08, 0, 0, 0],
@@ -263,7 +263,7 @@ def test_energy_density(self):
         )
 
 
-class TestElasticTensorExpansion(PymatgenTest):
+class TestElasticTensorExpansion:
     def setUp(self):
         with open(f"{TEST_DIR}/test_toec_data.json") as file:
             self.data_dict = json.load(file)
@@ -364,7 +364,7 @@ def test_get_yield_stress(self):
         self.exp_cu_4.get_yield_stress([1, 0, 0])
 
 
-class TestNthOrderElasticTensor(PymatgenTest):
+class TestNthOrderElasticTensor:
     def setUp(self):
         with open(f"{TEST_DIR}/test_toec_data.json") as file:
             self.data_dict = json.load(file)
@@ -401,7 +401,7 @@ def test_energy_density(self):
         self.c3.energy_density(self.strains[0])
 
 
-class TestDiffFit(PymatgenTest):
+class TestDiffFit:
     """Test various functions related to diff fitting."""
 
     def setUp(self):
diff --git a/tests/analysis/elasticity/test_strain.py b/tests/analysis/elasticity/test_strain.py
index 9679fb367cd..53c33a5192a 100644
--- a/tests/analysis/elasticity/test_strain.py
+++ b/tests/analysis/elasticity/test_strain.py
@@ -7,10 +7,9 @@
 from pymatgen.analysis.elasticity.strain import Deformation, DeformedStructureSet, Strain, convert_strain_to_deformation
 from pymatgen.core.structure import Structure
 from pymatgen.core.tensors import Tensor
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestDeformation(PymatgenTest):
+class TestDeformation:
     def setUp(self):
         self.norm_defo = Deformation.from_index_amount((0, 0), 0.02)
         self.ind_defo = Deformation.from_index_amount((0, 1), 0.02)
@@ -81,7 +80,7 @@ def test_apply_to_structure(self):
             assert_allclose(new_coord, defo_coord)
 
 
-class TestStrain(PymatgenTest):
+class TestStrain:
     def setUp(self):
         self.norm_str = Strain.from_deformation([[1.02, 0, 0], [0, 1, 0], [0, 0, 1]])
         self.ind_str = Strain.from_deformation([[1, 0.02, 0], [0, 1, 0], [0, 0, 1]])
@@ -142,7 +141,7 @@ def test_convert_strain_to_deformation(self):
             assert_allclose(defo.green_lagrange_strain, strain)
 
 
-class TestDeformedStructureSet(PymatgenTest):
+class TestDeformedStructureSet:
     def setUp(self):
         self.structure = self.get_structure("Sn")
         self.default_dss = DeformedStructureSet(self.structure)
diff --git a/tests/analysis/elasticity/test_stress.py b/tests/analysis/elasticity/test_stress.py
index 9d1dc98ad33..58e0bf1507c 100644
--- a/tests/analysis/elasticity/test_stress.py
+++ b/tests/analysis/elasticity/test_stress.py
@@ -7,10 +7,9 @@
 
 from pymatgen.analysis.elasticity.strain import Deformation
 from pymatgen.analysis.elasticity.stress import Stress
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestStress(PymatgenTest):
+class TestStress:
     def setUp(self):
         self.rand_stress = Stress(np.random.default_rng().standard_normal((3, 3)))
         self.symm_stress = Stress([[0.51, 2.29, 2.42], [2.29, 5.14, 5.07], [2.42, 5.07, 5.33]])
diff --git a/tests/analysis/ferroelectricity/test_polarization.py b/tests/analysis/ferroelectricity/test_polarization.py
index 57236ff98c4..71bb13d45e3 100644
--- a/tests/analysis/ferroelectricity/test_polarization.py
+++ b/tests/analysis/ferroelectricity/test_polarization.py
@@ -13,7 +13,7 @@
 from pymatgen.core.structure import Structure
 from pymatgen.io.vasp.inputs import Potcar
 from pymatgen.io.vasp.outputs import Outcar
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/vasp/fixtures/BTO_221_99_polarization"
 bto_folders = ["nonpolar_polarization"]
@@ -38,7 +38,7 @@
 )
 
 
-class TestUtils(PymatgenTest):
+class TestUtils:
     def setUp(self):
         self.potcar = Potcar.from_file(f"{TEST_DIR}/POTCAR")
         self.zval_dict = {"Ba": 10, "Ti": 10, "O": 6}
@@ -54,7 +54,7 @@ def test_get_total_ionic_dipole(self):
         assert_allclose(p_ion, self.ions[-1].ravel().tolist())
 
 
-class TestPolarization(PymatgenTest):
+class TestPolarization:
     def setUp(self):
         self.p_ions = ions
         self.p_ions_outcar = np.array(
@@ -258,7 +258,7 @@ def test_smoothness(self):
         assert_allclose(self.smoothness_all_in_polar, smoothness)
 
 
-class TestEnergyTrend(PymatgenTest):
+class TestEnergyTrend:
     def setUp(self):
         self.energies = [
             -7.97738049,
diff --git a/tests/analysis/interfaces/test_coherent_interface.py b/tests/analysis/interfaces/test_coherent_interface.py
index e2a19a73915..2e6bc1ba1bc 100644
--- a/tests/analysis/interfaces/test_coherent_interface.py
+++ b/tests/analysis/interfaces/test_coherent_interface.py
@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-import unittest
+from unittest import TestCase
 
 from numpy.testing import assert_allclose
 
@@ -14,10 +14,9 @@
 from pymatgen.core.lattice import Lattice
 from pymatgen.core.structure import Structure
 from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestInterfaceBuilder(PymatgenTest):
+class TestInterfaceBuilder:
     @classmethod
     def setUpClass(cls):
         si_struct = cls.get_structure("Si")
@@ -51,7 +50,7 @@ def test_coherent_interface_builder(self):
         assert len(list(builder.get_interfaces(termination=("O2_Pmmm_1", "Si_R-3m_1")))) >= 6
 
 
-class TestCoherentInterfaceBuilder(unittest.TestCase):
+class TestCoherentInterfaceBuilder(TestCase):
     def setUp(self):
         # build substrate & film structure
         basis = [[0, 0, 0], [0.25, 0.25, 0.25]]
diff --git a/tests/analysis/interfaces/test_zsl.py b/tests/analysis/interfaces/test_zsl.py
index 25ab77950e1..cc7c8657403 100644
--- a/tests/analysis/interfaces/test_zsl.py
+++ b/tests/analysis/interfaces/test_zsl.py
@@ -13,7 +13,6 @@
     vec_area,
 )
 from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
-from pymatgen.util.testing import PymatgenTest
 
 __author__ = "Shyam Dwaraknath"
 __copyright__ = "Copyright 2016, The Materials Project"
@@ -23,7 +22,7 @@
 __date__ = "2/5/16"
 
 
-class TestZSLGen(PymatgenTest):
+class TestZSLGen:
     def setUp(self):
         # Film VO2
         self.film = SpacegroupAnalyzer(self.get_structure("VO2"), symprec=0.1).get_conventional_standard_structure()
diff --git a/tests/analysis/solar/test_slme.py b/tests/analysis/solar/test_slme.py
index 3ccf3256d11..334e7d63a4c 100644
--- a/tests/analysis/solar/test_slme.py
+++ b/tests/analysis/solar/test_slme.py
@@ -3,12 +3,12 @@
 from pytest import approx
 
 from pymatgen.analysis.solar.slme import optics, slme
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/solar"
 
 
-class TestSolar(PymatgenTest):
+class TestSolar:
     def test_slme_from_vasprun(self):
         en, abz, dir_gap, indir_gap = optics(f"{TEST_DIR}/vasprun.xml")
         abz *= 100.0
diff --git a/tests/analysis/structure_prediction/test_substitutor.py b/tests/analysis/structure_prediction/test_substitutor.py
index 6965408afcc..be05f0bc60d 100644
--- a/tests/analysis/structure_prediction/test_substitutor.py
+++ b/tests/analysis/structure_prediction/test_substitutor.py
@@ -20,7 +20,7 @@ def get_table():
         return json.load(file)
 
 
-class TestSubstitutor(PymatgenTest):
+class TestSubstitutor:
     def setUp(self):
         self.substitutor = Substitutor(threshold=1e-3, lambda_table=get_table(), alpha=-5.0)
 
diff --git a/tests/analysis/structure_prediction/test_volume_predictor.py b/tests/analysis/structure_prediction/test_volume_predictor.py
index 20ecf2bd24b..f75df75cf3a 100644
--- a/tests/analysis/structure_prediction/test_volume_predictor.py
+++ b/tests/analysis/structure_prediction/test_volume_predictor.py
@@ -10,7 +10,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/structure_prediction"
 
 
-class TestRLSVolumePredictor(PymatgenTest):
+class TestRLSVolumePredictor:
     def test_predict(self):
         struct = PymatgenTest.get_structure("CsCl")
         nacl = PymatgenTest.get_structure("CsCl")
@@ -77,7 +77,7 @@ def test_modes(self):
         assert vol_pred.predict(cs_cl, na_cl) == approx(342.84905395082535)
 
 
-class TestDLSVolumePredictor(PymatgenTest):
+class TestDLSVolumePredictor:
     def test_predict(self):
         vol_pred = DLSVolumePredictor()
         p_fast = DLSVolumePredictor(cutoff=0.0)  # for speed on compressed cells
diff --git a/tests/analysis/test_adsorption.py b/tests/analysis/test_adsorption.py
index ced3948a366..6a9dd3b070d 100644
--- a/tests/analysis/test_adsorption.py
+++ b/tests/analysis/test_adsorption.py
@@ -8,10 +8,9 @@
 from pymatgen.core.structure import Molecule, Structure
 from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
 from pymatgen.util.coord import in_coord_list
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestAdsorbateSiteFinder(PymatgenTest):
+class TestAdsorbateSiteFinder:
     def setUp(self):
         self.structure = Structure.from_spacegroup("Fm-3m", Lattice.cubic(3.5), ["Ni"], [[0, 0, 0]])
         lattice = Lattice.cubic(3.010)
diff --git a/tests/analysis/test_bond_valence.py b/tests/analysis/test_bond_valence.py
index a2e0db2ce0c..06c0fef3dc3 100644
--- a/tests/analysis/test_bond_valence.py
+++ b/tests/analysis/test_bond_valence.py
@@ -5,12 +5,12 @@
 
 from pymatgen.analysis.bond_valence import BVAnalyzer, calculate_bv_sum, calculate_bv_sum_unordered
 from pymatgen.core import Composition, Species, Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/bond_valence"
 
 
-class TestBVAnalyzer(PymatgenTest):
+class TestBVAnalyzer:
     def setUp(self):
         self.analyzer = BVAnalyzer()
 
@@ -44,7 +44,7 @@ def test_get_oxi_state_structure(self):
         assert Species("Mn4+") in oxi_struct.composition.elements
 
 
-class TestBondValenceSum(PymatgenTest):
+class TestBondValenceSum:
     def test_calculate_bv_sum(self):
         struct = Structure.from_file(f"{TEST_DIR}/LiMn2O4.json")
         neighbors = struct.get_neighbors(struct[0], 3.0)
diff --git a/tests/analysis/test_chempot_diagram.py b/tests/analysis/test_chempot_diagram.py
index 43dfd957b0d..192e4aaf9de 100644
--- a/tests/analysis/test_chempot_diagram.py
+++ b/tests/analysis/test_chempot_diagram.py
@@ -12,12 +12,12 @@
 )
 from pymatgen.core.composition import Element
 from pymatgen.entries.entry_tools import EntrySet
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis"
 
 
-class TestChemicalPotentialDiagram(PymatgenTest):
+class TestChemicalPotentialDiagram:
     def setUp(self):
         self.entries = EntrySet.from_csv(f"{TEST_DIR}/pd_entries_test.csv")
         self.cpd_ternary, self.cpd_ternary_formal = (
diff --git a/tests/analysis/test_dimensionality.py b/tests/analysis/test_dimensionality.py
index 8b99c6fd5e2..0f1139e7072 100644
--- a/tests/analysis/test_dimensionality.py
+++ b/tests/analysis/test_dimensionality.py
@@ -15,10 +15,10 @@
 from pymatgen.analysis.graphs import StructureGraph
 from pymatgen.analysis.local_env import CrystalNN
 from pymatgen.core.structure import Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 
-class TestLarsenDimensionality(PymatgenTest):
+class TestLarsenDimensionality:
     def setUp(self):
         cnn = CrystalNN()
         self.lifepo = cnn.get_bonded_structure(self.get_structure("LiFePO4"))
@@ -114,7 +114,7 @@ def test_zero_d_to_molecule_graph(self):
         assert len(mol_graph.molecule) == 12
 
 
-class TestCheonDimensionality(PymatgenTest):
+class TestCheonDimensionality:
     def test_get_dimensionality(self):
         struct = self.get_structure("LiFePO4")
         assert get_dimensionality_cheon(struct) == "intercalated ion"
@@ -152,7 +152,7 @@ def test_tricky_structure(self):
         assert get_dimensionality_cheon(tricky_structure, larger_cell=True) == "3D"
 
 
-class TestGoraiDimensionality(PymatgenTest):
+class TestGoraiDimensionality:
     def test_get_dimensionality(self):
         struct = self.get_structure("LiFePO4")
         assert get_dimensionality_gorai(struct) == 3
diff --git a/tests/analysis/test_disorder.py b/tests/analysis/test_disorder.py
index f1fbd2f58d5..a00de0a8035 100644
--- a/tests/analysis/test_disorder.py
+++ b/tests/analysis/test_disorder.py
@@ -4,10 +4,9 @@
 
 from pymatgen.analysis.disorder import get_warren_cowley_parameters
 from pymatgen.core import Element, Structure
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestOrderParameter(PymatgenTest):
+class TestOrderParameter:
     def test_compute_warren_cowley_parameters(self):
         struct = Structure.from_prototype("CsCl", ["Mo", "W"], a=4)
         aij = get_warren_cowley_parameters(struct, r=3.4, dr=0.3)
diff --git a/tests/analysis/test_eos.py b/tests/analysis/test_eos.py
index 9a839f8279b..da507c32035 100644
--- a/tests/analysis/test_eos.py
+++ b/tests/analysis/test_eos.py
@@ -5,10 +5,9 @@
 from pytest import approx
 
 from pymatgen.analysis.eos import EOS, NumericalEOS
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestEOS(PymatgenTest):
+class TestEOS:
     def setUp(self):
         # Si data from Cormac
         self.volumes = [
diff --git a/tests/analysis/test_fragmenter.py b/tests/analysis/test_fragmenter.py
index 211d7e3b7d1..c1efc2e69d6 100644
--- a/tests/analysis/test_fragmenter.py
+++ b/tests/analysis/test_fragmenter.py
@@ -8,7 +8,7 @@
 from pymatgen.analysis.graphs import MoleculeGraph
 from pymatgen.analysis.local_env import OpenBabelNN
 from pymatgen.core.structure import Molecule
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Samuel Blau"
 __email__ = "samblau1@gmail.com"
@@ -17,7 +17,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/local_env/fragmenter_files"
 
 
-class TestFragmentMolecule(PymatgenTest):
+class TestFragmentMolecule:
     @classmethod
     def setUpClass(cls):
         cls.pc = Molecule.from_file(f"{TEST_DIR}/PC.xyz")
diff --git a/tests/analysis/test_graphs.py b/tests/analysis/test_graphs.py
index ad42533435c..9e0c9f9f83c 100644
--- a/tests/analysis/test_graphs.py
+++ b/tests/analysis/test_graphs.py
@@ -24,7 +24,7 @@
 from pymatgen.command_line.critic2_caller import Critic2Analysis
 from pymatgen.core import Lattice, Molecule, Site, Structure
 from pymatgen.core.structure import FunctionalGroups
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 try:
     from openbabel import openbabel
@@ -46,7 +46,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/graphs"
 
 
-class TestStructureGraph(PymatgenTest):
+class TestStructureGraph:
     def setUp(self):
         # trivial example, simple square lattice for testing
         structure = Structure(Lattice.tetragonal(5, 50), ["H"], [[0, 0, 0]])
diff --git a/tests/analysis/test_local_env.py b/tests/analysis/test_local_env.py
index ac2ab8b099d..a6214fe1311 100644
--- a/tests/analysis/test_local_env.py
+++ b/tests/analysis/test_local_env.py
@@ -40,7 +40,7 @@
     solid_angle,
 )
 from pymatgen.core import Element, Lattice, Molecule, Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/local_env/fragmenter_files"
 
@@ -54,7 +54,7 @@ def test_opt_params():
     assert cn_opt_params == CN_OPT_PARAMS
 
 
-class TestValenceIonicRadiusEvaluator(PymatgenTest):
+class TestValenceIonicRadiusEvaluator:
     def setUp(self):
         """Setup MgO rocksalt structure for testing Vacancy."""
         mgo_latt = np.eye(3) * 4.212
@@ -89,7 +89,7 @@ def test_radii_ionic_structure(self):
             assert rad in {0.86, 1.26}
 
 
-class TestVoronoiNN(PymatgenTest):
+class TestVoronoiNN:
     def setUp(self):
         self.struct = self.get_structure("LiFePO4")
         self.nn = VoronoiNN(targets=[Element("O")])
@@ -260,7 +260,7 @@ def test_filtered(self):
         assert [len(x) for x in all_nns] == [8] * 16
 
 
-class TestJmolNN(PymatgenTest):
+class TestJmolNN:
     def setUp(self):
         self.jmol = JmolNN()
         self.jmol_update = JmolNN(el_radius_updates={"Li": 1})
@@ -290,7 +290,7 @@ def test_get_nn(self):
         assert len(self.jmol_update.get_nn(struct, 0)) == 2
 
 
-class TestIsayevNN(PymatgenTest):
+class TestIsayevNN:
     def test_get_nn(self):
         inn = IsayevNN()
         struct = self.get_structure("LiFePO4")
@@ -301,7 +301,7 @@ def test_get_nn(self):
         assert len(inn.get_nn(struct, 0)) == 2
 
 
-class TestOpenBabelNN(PymatgenTest):
+class TestOpenBabelNN:
     def setUp(self):
         pytest.importorskip("openbabel")
         self.benzene = Molecule.from_file(f"{TEST_DIR}/../benzene.xyz")
@@ -333,7 +333,7 @@ def test_nn_length(self):
         assert strategy.get_nn_info(self.acetylene, 0)[0]["weight"] == approx(1.19, abs=1e-2)
 
 
-class TestCovalentBondNN(PymatgenTest):
+class TestCovalentBondNN:
     def setUp(self):
         self.benzene = Molecule.from_file(f"{TEST_DIR}/../benzene.xyz")
         self.acetylene = Molecule.from_file(f"{TEST_FILES_DIR}/io/xyz/acetylene.xyz")
@@ -372,7 +372,7 @@ def test_bonded_structure(self):
         assert len(acetylene.graph.nodes) == 4
 
 
-class TestMiniDistNN(PymatgenTest):
+class TestMiniDistNN:
     def setUp(self):
         self.diamond = Structure(
             Lattice([[2.189, 0, 1.264], [0.73, 2.064, 1.264], [0, 0, 2.528]]),
@@ -485,7 +485,7 @@ def test_get_local_order_params(self):
         assert ops["octahedral"] == approx(0.9999995266669)
 
 
-class TestMotifIdentification(PymatgenTest):
+class TestMotifIdentification:
     def setUp(self):
         self.silicon = Structure(
             Lattice.cubic(5.47),
@@ -583,7 +583,7 @@ def test_get_neighbors_of_site_with_index(self):
         assert len(get_neighbors_of_site_with_index(self.diamond, 0, approach="min_VIRE")) == 4
 
 
-class TestNearNeighbor(PymatgenTest):
+class TestNearNeighbor:
     def setUp(self):
         self.diamond = Structure(
             Lattice([[2.189, 0, 1.264], [0.73, 2.064, 1.264], [0, 0, 2.528]]),
@@ -617,7 +617,7 @@ def test_on_disorder_options(self):
         )
 
 
-class TestLocalStructOrderParams(PymatgenTest):
+class TestLocalStructOrderParams:
     def setUp(self):
         self.single_bond = Structure(
             Lattice.cubic(10),
@@ -1182,7 +1182,7 @@ def test_get_order_parameters(self):
             ops_101.get_order_parameters(self.bcc, 0, indices_neighs=[2])
 
 
-class TestCrystalNN(PymatgenTest):
+class TestCrystalNN:
     def setUp(self):
         self.lifepo4 = self.get_structure("LiFePO4")
         self.lifepo4.add_oxidation_state_by_guess()
@@ -1329,7 +1329,7 @@ def test_get_bonded_structure(self):
             cnn.get_bonded_structure(self.disordered_struct, 0, on_disorder="error")
 
 
-class TestCutOffDictNN(PymatgenTest):
+class TestCutOffDictNN:
     def setUp(self):
         self.diamond = Structure(
             Lattice([[2.189, 0, 1.264], [0.73, 2.064, 1.264], [0, 0, 2.528]]),
@@ -1355,7 +1355,7 @@ def test_from_preset(self):
 
 
 @pytest.mark.skipif(not which("critic2"), reason="critic2 executable not present")
-class TestCritic2NN(PymatgenTest):
+class TestCritic2NN:
     def setUp(self):
         self.diamond = Structure(
             Lattice([[2.189, 0, 1.264], [0.73, 2.064, 1.264], [0, 0, 2.528]]),
@@ -1369,7 +1369,7 @@ def test_cn(self):
         # assert nn.get_cn(self.diamond, 0) == 4
 
 
-class TestMetalEdgeExtender(PymatgenTest):
+class TestMetalEdgeExtender:
     def setUp(self):
         self.LiEC = Molecule.from_file(f"{TEST_DIR}/LiEC.xyz")
         self.phsh = Molecule.from_file(f"{TEST_DIR}/phsh.xyz")
diff --git a/tests/analysis/test_nmr.py b/tests/analysis/test_nmr.py
index 14490ec7a0c..e90dfddc6ca 100644
--- a/tests/analysis/test_nmr.py
+++ b/tests/analysis/test_nmr.py
@@ -5,10 +5,9 @@
 from pytest import approx
 
 from pymatgen.analysis.nmr import ChemicalShielding, ElectricFieldGradient
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestChemicalShieldingNotation(PymatgenTest):
+class TestChemicalShieldingNotation:
     def test_construction(self):
         cs = ChemicalShielding(np.arange(9).reshape((3, 3)))
         assert cs.shape == (3, 3)
@@ -46,7 +45,7 @@ def test_notations(self):
         assert mary1.kappa == approx(0.8337, abs=1e-5)
 
 
-class TestElectricFieldGradient(PymatgenTest):
+class TestElectricFieldGradient:
     def test_construction(self):
         efg = ElectricFieldGradient(np.arange(9).reshape((3, 3)))
         assert efg.shape == (3, 3)
diff --git a/tests/analysis/test_phase_diagram.py b/tests/analysis/test_phase_diagram.py
index 934ba59fa9d..b534aba8ddc 100644
--- a/tests/analysis/test_phase_diagram.py
+++ b/tests/analysis/test_phase_diagram.py
@@ -32,7 +32,7 @@
 from pymatgen.core import Composition, DummySpecies, Element
 from pymatgen.entries.computed_entries import ComputedEntry
 from pymatgen.entries.entry_tools import EntrySet
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis"
 
@@ -179,7 +179,7 @@ def test_normalize(self):
         assert norm_entry.composition == expected_comp
 
 
-class TestPhaseDiagram(PymatgenTest):
+class TestPhaseDiagram:
     def setUp(self):
         self.entries = EntrySet.from_csv(f"{TEST_DIR}/pd_entries_test.csv")
         self.pd = PhaseDiagram(self.entries)
diff --git a/tests/analysis/test_piezo.py b/tests/analysis/test_piezo.py
index bf3eb7534c2..0621591b44c 100644
--- a/tests/analysis/test_piezo.py
+++ b/tests/analysis/test_piezo.py
@@ -7,7 +7,6 @@
 from numpy.testing import assert_allclose, assert_array_equal
 
 from pymatgen.analysis.piezo import PiezoTensor
-from pymatgen.util.testing import PymatgenTest
 
 __author__ = "Shyam Dwaraknath"
 __version__ = "0.1"
@@ -17,7 +16,7 @@
 __date__ = "4/1/16"
 
 
-class TestPiezo(PymatgenTest):
+class TestPiezo:
     def setUp(self):
         self.piezo_struct = self.get_structure("BaNiO3")
         self.voigt_matrix = np.array(
diff --git a/tests/analysis/test_piezo_sensitivity.py b/tests/analysis/test_piezo_sensitivity.py
index 757215a30e4..b14e90e0250 100644
--- a/tests/analysis/test_piezo_sensitivity.py
+++ b/tests/analysis/test_piezo_sensitivity.py
@@ -17,7 +17,7 @@
     rand_piezo,
 )
 from pymatgen.io.phonopy import get_phonopy_structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 try:
     from phonopy import Phonopy
@@ -34,7 +34,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/piezo_sensitivity"
 
 
-class TestPiezoSensitivity(PymatgenTest):
+class TestPiezoSensitivity:
     def setUp(self):
         self.piezo_struct = self.get_structure("Pb2TiZrO6")
         self.IST = np.load(f"{TEST_DIR}/pztist.npy", allow_pickle=True)
diff --git a/tests/analysis/test_pourbaix_diagram.py b/tests/analysis/test_pourbaix_diagram.py
index 22066499257..98f2dacc9cc 100644
--- a/tests/analysis/test_pourbaix_diagram.py
+++ b/tests/analysis/test_pourbaix_diagram.py
@@ -12,12 +12,12 @@
 from pymatgen.core.composition import Composition
 from pymatgen.core.ion import Ion
 from pymatgen.entries.computed_entries import ComputedEntry
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/pourbaix_diagram"
 
 
-class TestPourbaixEntry(PymatgenTest):
+class TestPourbaixEntry:
     """Test all functions using a fictitious entry"""
 
     def setUp(self):
diff --git a/tests/analysis/test_prototypes.py b/tests/analysis/test_prototypes.py
index d2a16258d03..49f42675ea5 100644
--- a/tests/analysis/test_prototypes.py
+++ b/tests/analysis/test_prototypes.py
@@ -1,10 +1,9 @@
 from __future__ import annotations
 
 from pymatgen.analysis.prototypes import AflowPrototypeMatcher
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestAflowPrototypeMatcher(PymatgenTest):
+class TestAflowPrototypeMatcher:
     def test_prototype_matching(self):
         af = AflowPrototypeMatcher()
 
diff --git a/tests/analysis/test_structure_analyzer.py b/tests/analysis/test_structure_analyzer.py
index a7da910eff0..1b01946b217 100644
--- a/tests/analysis/test_structure_analyzer.py
+++ b/tests/analysis/test_structure_analyzer.py
@@ -18,10 +18,10 @@
 )
 from pymatgen.core import Element, Lattice, Structure
 from pymatgen.io.vasp.outputs import Xdatcar
-from pymatgen.util.testing import VASP_IN_DIR, VASP_OUT_DIR, PymatgenTest
+from pymatgen.util.testing import VASP_IN_DIR, VASP_OUT_DIR
 
 
-class TestVoronoiAnalyzer(PymatgenTest):
+class TestVoronoiAnalyzer:
     def setUp(self):
         self.structs = Xdatcar(f"{VASP_OUT_DIR}/XDATCAR.MD").structures
         self.struct = self.structs[1]
@@ -62,7 +62,7 @@ def test_get_percentage_bond_dist_changes(self):
                 assert approx(v2) == -0.009204092115527862
 
 
-class TestVoronoiConnectivity(PymatgenTest):
+class TestVoronoiConnectivity:
     def test_connectivity_array(self):
         vc = VoronoiConnectivity(self.get_structure("LiFePO4"))
         ca = vc.connectivity_array
@@ -78,7 +78,7 @@ def test_connectivity_array(self):
         assert_allclose(site.frac_coords, expected)
 
 
-class TestMiscFunction(PymatgenTest):
+class TestMiscFunction:
     def test_average_coordination_number(self):
         xdatcar = Xdatcar(f"{VASP_OUT_DIR}/XDATCAR.MD")
         coordination_numbers = average_coordination_number(xdatcar.structures, freq=1)
diff --git a/tests/analysis/test_structure_matcher.py b/tests/analysis/test_structure_matcher.py
index 5a71019ebe2..c47da09efab 100644
--- a/tests/analysis/test_structure_matcher.py
+++ b/tests/analysis/test_structure_matcher.py
@@ -17,12 +17,12 @@
 )
 from pymatgen.core import Element, Lattice, Structure, SymmOp
 from pymatgen.util.coord import find_in_coord_list_pbc
-from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/structure_matcher"
 
 
-class TestStructureMatcher(PymatgenTest):
+class TestStructureMatcher:
     def setUp(self):
         with open(f"{TEST_FILES_DIR}/entries/TiO2_entries.json") as file:
             entries = json.load(file, cls=MontyDecoder)
diff --git a/tests/analysis/test_surface_analysis.py b/tests/analysis/test_surface_analysis.py
index 5492d9aefa6..cc0aaa6f0e3 100644
--- a/tests/analysis/test_surface_analysis.py
+++ b/tests/analysis/test_surface_analysis.py
@@ -9,7 +9,7 @@
 
 from pymatgen.analysis.surface_analysis import NanoscaleStability, SlabEntry, SurfaceEnergyPlotter, WorkFunctionAnalyzer
 from pymatgen.entries.computed_entries import ComputedStructureEntry
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Richard Tran"
 __copyright__ = "Copyright 2012, The Materials Project"
@@ -22,7 +22,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/surfaces"
 
 
-class TestSlabEntry(PymatgenTest):
+class TestSlabEntry:
     def setUp(self):
         with open(f"{TEST_DIR}/ucell_entries.txt") as file:
             ucell_entries = json.loads(file.read())
@@ -118,7 +118,7 @@ def test_cleaned_up_slab(self):
                         assert slab_clean.composition.reduced_composition == clean.composition.reduced_composition
 
 
-class TestSurfaceEnergyPlotter(PymatgenTest):
+class TestSurfaceEnergyPlotter:
     def setUp(self):
         entry_dict = get_entry_dict(f"{TEST_DIR}/Cu_entries.txt")
         self.Cu_entry_dict = entry_dict
@@ -292,7 +292,7 @@ def test_surface_chempot_range_map(self):
                 analyzer.chempot_vs_gamma_facet(hkl)
 
 
-class TestWorkFunctionAnalyzer(PymatgenTest):
+class TestWorkFunctionAnalyzer:
     def setUp(self):
         self.kwargs = {
             "poscar_filename": f"{TEST_DIR}/CONTCAR.relax1.gz",
@@ -309,7 +309,7 @@ def test_is_converged(self):
         assert self.wf_analyzer.is_converged()
 
 
-class TestNanoscaleStability(PymatgenTest):
+class TestNanoscaleStability:
     def setUp(self):
         # Load all entries
         La_hcp_entry_dict = get_entry_dict(f"{TEST_DIR}/La_hcp_entries.txt")
diff --git a/tests/analysis/test_transition_state.py b/tests/analysis/test_transition_state.py
index 96841bc482a..4ca1cf08339 100644
--- a/tests/analysis/test_transition_state.py
+++ b/tests/analysis/test_transition_state.py
@@ -6,7 +6,7 @@
 from numpy.testing import assert_allclose
 
 from pymatgen.analysis.transition_state import NEBAnalysis, combine_neb_plots
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 """
 TODO: Modify unittest doc.
@@ -23,7 +23,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/io/vasp/fixtures/neb_analysis"
 
 
-class TestNEBAnalysis(PymatgenTest):
+class TestNEBAnalysis:
     def test_run(self):
         neb_analysis1 = NEBAnalysis.from_dir(f"{TEST_DIR}/neb1/neb")
         neb_analysis1_from_dict = NEBAnalysis.from_dict(neb_analysis1.as_dict())
diff --git a/tests/analysis/test_wulff.py b/tests/analysis/test_wulff.py
index 768d079e2da..527a24fb4a7 100644
--- a/tests/analysis/test_wulff.py
+++ b/tests/analysis/test_wulff.py
@@ -9,7 +9,7 @@
 from pymatgen.core.structure import Structure
 from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
 from pymatgen.util.coord import in_coord_list
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Zihan Xu, Richard Tran, Balachandran Radhakrishnan"
 __copyright__ = "Copyright 2013, The Materials Virtual Lab"
@@ -21,7 +21,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/wulff"
 
 
-class TestWulffShape(PymatgenTest):
+class TestWulffShape:
     def setUp(self):
         with open(f"{TEST_DIR}/surface_samples.json") as data_file:
             surface_properties = json.load(data_file)
diff --git a/tests/analysis/test_xps.py b/tests/analysis/test_xps.py
index 45b250e3100..f2260c82717 100644
--- a/tests/analysis/test_xps.py
+++ b/tests/analysis/test_xps.py
@@ -2,10 +2,10 @@
 
 from pymatgen.analysis.xps import XPS
 from pymatgen.io.vasp import Vasprun
-from pymatgen.util.testing import VASP_OUT_DIR, PymatgenTest
+from pymatgen.util.testing import VASP_OUT_DIR
 
 
-class TestXPS(PymatgenTest):
+class TestXPS:
     def test_from_dos(self):
         vasp_run = Vasprun(f"{VASP_OUT_DIR}/vasprun.LiF.xml.gz")
         dos = vasp_run.complete_dos
diff --git a/tests/analysis/topological/test_spillage.py b/tests/analysis/topological/test_spillage.py
index 39224cdfc52..254b6002dc3 100644
--- a/tests/analysis/topological/test_spillage.py
+++ b/tests/analysis/topological/test_spillage.py
@@ -3,12 +3,12 @@
 from pytest import approx
 
 from pymatgen.analysis.topological.spillage import SOCSpillage
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/topological"
 
 
-class TestSolar(PymatgenTest):
+class TestSolar:
     def test_spillage_from_vasprun(self):
         wf_noso = f"{TEST_DIR}/WAVECAR-NonSOC"
         wf_so = f"{TEST_DIR}/WAVECAR-SOC"
diff --git a/tests/analysis/xas/test_spectrum.py b/tests/analysis/xas/test_spectrum.py
index 92a04879dc3..16553553e84 100644
--- a/tests/analysis/xas/test_spectrum.py
+++ b/tests/analysis/xas/test_spectrum.py
@@ -10,7 +10,7 @@
 
 from pymatgen.analysis.xas.spectrum import XAS, site_weighted_spectrum
 from pymatgen.core import Element
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/spectrum_test"
 
@@ -28,7 +28,7 @@
     site2_xanes_dict = json.load(file, cls=MontyDecoder)
 
 
-class TestXAS(PymatgenTest):
+class TestXAS:
     def setUp(self):
         self.k_xanes = XAS.from_dict(k_xanes_dict)
         self.k_exafs = XAS.from_dict(k_exafs_dict)
diff --git a/tests/apps/battery/test_analyzer.py b/tests/apps/battery/test_analyzer.py
index eea99df2ecb..5e3fa0cd9f0 100644
--- a/tests/apps/battery/test_analyzer.py
+++ b/tests/apps/battery/test_analyzer.py
@@ -5,10 +5,10 @@
 
 from pymatgen.apps.battery.analyzer import BatteryAnalyzer
 from pymatgen.core.structure import Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 
-class TestBatteryAnalyzer(PymatgenTest):
+class TestBatteryAnalyzer:
     def load_from_cif(self, filename, oxidations, working_ion="Li"):
         struct = Structure.from_file(f"{TEST_FILES_DIR}/cif/{filename}")
         struct.add_oxidation_state_by_element(oxidations)
diff --git a/tests/command_line/test_bader_caller.py b/tests/command_line/test_bader_caller.py
index ad39f8c6b61..3d0f73e58ed 100644
--- a/tests/command_line/test_bader_caller.py
+++ b/tests/command_line/test_bader_caller.py
@@ -10,13 +10,13 @@
 from pytest import approx
 
 from pymatgen.command_line.bader_caller import BaderAnalysis, bader_analysis_from_path
-from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/command_line/bader"
 
 
 @pytest.mark.skipif(not which("bader"), reason="bader executable not present")
-class TestBaderAnalysis(PymatgenTest):
+class TestBaderAnalysis:
     def setUp(self):
         warnings.catch_warnings()
 
diff --git a/tests/command_line/test_enumlib_caller.py b/tests/command_line/test_enumlib_caller.py
index aa3cebff4a3..b55ff9c2fea 100644
--- a/tests/command_line/test_enumlib_caller.py
+++ b/tests/command_line/test_enumlib_caller.py
@@ -11,14 +11,14 @@
 from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
 from pymatgen.transformations.site_transformations import RemoveSitesTransformation
 from pymatgen.transformations.standard_transformations import SubstitutionTransformation
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 ENUM_CMD = which("enum.x") or which("multienum.x")
 MAKESTR_CMD = which("makestr.x") or which("makeStr.x") or which("makeStr.py")
 
 
 @pytest.mark.skipif(not (ENUM_CMD and MAKESTR_CMD), reason="enumlib not present.")
-class TestEnumlibAdaptor(PymatgenTest):
+class TestEnumlibAdaptor:
     def test_init(self):
         struct = self.get_structure("LiFePO4")
         sub_trans = SubstitutionTransformation({"Li": {"Li": 0.5}})
diff --git a/tests/command_line/test_mcsqs_caller.py b/tests/command_line/test_mcsqs_caller.py
index ca9f8a018d6..b214f42b262 100644
--- a/tests/command_line/test_mcsqs_caller.py
+++ b/tests/command_line/test_mcsqs_caller.py
@@ -7,7 +7,7 @@
 
 from pymatgen.command_line.mcsqs_caller import run_mcsqs
 from pymatgen.core.structure import Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Handong Ling, Rachel Woods-Robinson"
 __maintainer__ = "Handong Ling, Rachel Woods-Robinson"
@@ -18,7 +18,7 @@
 
 
 @pytest.mark.skipif(not (which("mcsqs") and which("str2cif")), reason="mcsqs executable not present")
-class TestMcsqsCaller(PymatgenTest):
+class TestMcsqsCaller:
     def setUp(self):
         self.pzt_structs = loadfn(f"{TEST_DIR}/pzt-structs.json")
         self.pzt_structs2 = loadfn(f"{TEST_DIR}/pzt-structs-2.json")
diff --git a/tests/command_line/test_vampire_caller.py b/tests/command_line/test_vampire_caller.py
index e2e55a18486..cc8fb7c254c 100644
--- a/tests/command_line/test_vampire_caller.py
+++ b/tests/command_line/test_vampire_caller.py
@@ -8,13 +8,13 @@
 
 from pymatgen.command_line.vampire_caller import VampireCaller
 from pymatgen.core.structure import Structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/analysis/magnetic_orderings"
 
 
 @pytest.mark.skipif(not which("vampire-serial"), reason="vampire executable not present")
-class TestVampireCaller(PymatgenTest):
+class TestVampireCaller:
     @classmethod
     def setUpClass(cls):
         cls.Mn3Al = pd.read_json(f"{TEST_DIR}/Mn3Al.json")
diff --git a/tests/core/test_composition.py b/tests/core/test_composition.py
index 9c00c7678fd..dba2a3c67f6 100644
--- a/tests/core/test_composition.py
+++ b/tests/core/test_composition.py
@@ -13,10 +13,9 @@
 
 from pymatgen.core import Composition, DummySpecies, Element, Species
 from pymatgen.core.composition import ChemicalPotential
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestComposition(PymatgenTest):
+class TestComposition:
     def setUp(self):
         self.comps = [
             Composition("Li3Fe2(PO4)3"),
diff --git a/tests/core/test_interface.py b/tests/core/test_interface.py
index c2563cd2a7a..598759a40a8 100644
--- a/tests/core/test_interface.py
+++ b/tests/core/test_interface.py
@@ -8,12 +8,12 @@
 from pymatgen.core.structure import Structure
 from pymatgen.core.surface import SlabGenerator
 from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/core/grain_boundary"
 
 
-class TestGrainBoundary(PymatgenTest):
+class TestGrainBoundary:
     def setUp(self):
         self.Cu_conv = Structure.from_file(f"{TEST_DIR}/Cu_mp-30_conventional_standard.cif")
         GB_Cu_conv = GrainBoundaryGenerator(self.Cu_conv)
@@ -104,7 +104,7 @@ def test_as_dict_and_from_dict(self):
         assert_allclose(Cu_GB2_new.lattice.matrix, self.Cu_GB2.lattice.matrix)
 
 
-class TestGrainBoundaryGenerator(PymatgenTest):
+class TestGrainBoundaryGenerator:
     @classmethod
     def setUpClass(cls):
         cls.Cu_prim = Structure.from_file(f"{TEST_DIR}/Cu_mp-30_primitive.cif")
@@ -331,7 +331,7 @@ def test_get_rotation_angle_from_sigma(self):
         assert_allclose(close_angle, angle)
 
 
-class TestInterface(PymatgenTest):
+class TestInterface:
     def setUp(self):
         self.interface: Interface = self.get_structure("Si_SiO2_Interface")
 
diff --git a/tests/core/test_lattice.py b/tests/core/test_lattice.py
index 89a79e6330c..3bd111545ce 100644
--- a/tests/core/test_lattice.py
+++ b/tests/core/test_lattice.py
@@ -9,10 +9,9 @@
 
 from pymatgen.core.lattice import Lattice, get_points_in_spheres
 from pymatgen.core.operations import SymmOp
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestLattice(PymatgenTest):
+class TestLattice:
     def setUp(self):
         self.lattice = Lattice.cubic(10.0)
         self.cubic = self.lattice
diff --git a/tests/core/test_libxcfunc.py b/tests/core/test_libxcfunc.py
index 435b71c389e..56ab6335159 100644
--- a/tests/core/test_libxcfunc.py
+++ b/tests/core/test_libxcfunc.py
@@ -1,10 +1,9 @@
 from __future__ import annotations
 
 from pymatgen.core.libxcfunc import LibxcFunc
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestLibxcFunc(PymatgenTest):
+class TestLibxcFunc:
     def test_libxcfunc_api(self):
         """Testing libxcfunc_api."""
         # LDA correlation: Hedin & Lundqvist
diff --git a/tests/core/test_molecular_orbitals.py b/tests/core/test_molecular_orbitals.py
index 4476c856d17..5d193409c20 100644
--- a/tests/core/test_molecular_orbitals.py
+++ b/tests/core/test_molecular_orbitals.py
@@ -3,12 +3,11 @@
 import pytest
 
 from pymatgen.core.molecular_orbitals import MolecularOrbitals
-from pymatgen.util.testing import PymatgenTest
 
 test_case = MolecularOrbitals("NaCl")
 
 
-class TestMolecularOrbital(PymatgenTest):
+class TestMolecularOrbital:
     def test_max_electronegativity(self):
         test_elec_neg = 2.23
         assert test_elec_neg == test_case.max_electronegativity()
diff --git a/tests/core/test_operations.py b/tests/core/test_operations.py
index 1d775b09b92..6ece9b27eda 100644
--- a/tests/core/test_operations.py
+++ b/tests/core/test_operations.py
@@ -5,10 +5,9 @@
 
 from pymatgen.core.operations import MagSymmOp, SymmOp
 from pymatgen.electronic_structure.core import Magmom
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestSymmOp(PymatgenTest):
+class TestSymmOp:
     def setUp(self):
         self.op = SymmOp.from_axis_angle_and_translation([0, 0, 1], 30, translation_vec=[0, 0, 1])
 
@@ -236,7 +235,7 @@ def test_xyz(self):
         assert_allclose(symm_op.translation_vector, [0.5, 0.25, 0.75])
 
 
-class TestMagSymmOp(PymatgenTest):
+class TestMagSymmOp:
     def test_xyzt_string(self):
         xyzt_strings = ["x, y, z, +1", "x, y, z, -1", "-y+1/2, x+1/2, x+1/2, +1"]
 
diff --git a/tests/core/test_periodic_table.py b/tests/core/test_periodic_table.py
index a4a696a4f56..b02a017ec45 100644
--- a/tests/core/test_periodic_table.py
+++ b/tests/core/test_periodic_table.py
@@ -14,10 +14,9 @@
 from pymatgen.core.periodic_table import ElementBase, ElementType
 from pymatgen.core.units import Ha_to_eV
 from pymatgen.io.core import ParseError
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestElement(PymatgenTest):
+class TestElement:
     def test_init(self):
         assert Element("Fe").symbol == "Fe"
 
@@ -392,7 +391,7 @@ def test_isotope(self):
         ]
 
 
-class TestSpecies(PymatgenTest):
+class TestSpecies:
     def setUp(self):
         self.specie1 = Species.from_str("Fe2+")
         self.specie2 = Species("Fe", 3)
diff --git a/tests/core/test_sites.py b/tests/core/test_sites.py
index 28fb7b07e4c..2e619bf40aa 100644
--- a/tests/core/test_sites.py
+++ b/tests/core/test_sites.py
@@ -9,10 +9,9 @@
 
 from pymatgen.core import Composition, Element, Lattice, PeriodicSite, Site, Species
 from pymatgen.electronic_structure.core import Magmom
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestSite(PymatgenTest):
+class TestSite:
     def setUp(self):
         self.ordered_site = Site("Fe", [0.25, 0.35, 0.45])
         self.disordered_site = Site({"Fe": 0.5, "Mn": 0.5}, [0.25, 0.35, 0.45])
@@ -79,7 +78,7 @@ def test_setters(self):
             self.disordered_site.species = {"Cu": 0.5, "Gd": 0.6}
 
 
-class TestPeriodicSite(PymatgenTest):
+class TestPeriodicSite:
     def setUp(self):
         self.lattice = Lattice.cubic(10.0)
         self.si = Element("Si")
diff --git a/tests/core/test_spectrum.py b/tests/core/test_spectrum.py
index 2f8f208c175..f14b1506107 100644
--- a/tests/core/test_spectrum.py
+++ b/tests/core/test_spectrum.py
@@ -6,10 +6,9 @@
 from scipy import stats
 
 from pymatgen.core.spectrum import Spectrum
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestSpectrum(PymatgenTest):
+class TestSpectrum:
     def setUp(self):
         rng = np.random.default_rng()
         self.spec1 = Spectrum(np.arange(0, 10, 0.1), rng.standard_normal(100))
diff --git a/tests/core/test_structure.py b/tests/core/test_structure.py
index 7cb4abcbaf3..4b909a71411 100644
--- a/tests/core/test_structure.py
+++ b/tests/core/test_structure.py
@@ -44,7 +44,7 @@
 mcsqs_cmd = which("mcsqs")
 
 
-class TestNeighbor(PymatgenTest):
+class TestNeighbor:
     def test_msonable(self):
         struct = PymatgenTest.get_structure("Li2O")
         nn = struct.get_neighbors(struct[0], r=3)
@@ -63,7 +63,7 @@ def test_neighbor_labels(self):
             assert p_neighbor.label == label if label is not None else "C"
 
 
-class TestIStructure(PymatgenTest):
+class TestIStructure:
     def setUp(self):
         coords = [[0, 0, 0], [0.75, 0.5, 0.75]]
         self.lattice = Lattice(
@@ -965,7 +965,7 @@ def test_sites_setter(self):
         assert struct.sites == new_sites
 
 
-class TestStructure(PymatgenTest):
+class TestStructure:
     def setUp(self):
         coords = [[0, 0, 0], [0.75, 0.5, 0.75]]
         lattice = Lattice(
@@ -2032,7 +2032,7 @@ def test_struct_with_isotope(self):
         assert "Deuterium" not in [el.long_name for el in struct.composition.elements]
 
 
-class TestIMolecule(PymatgenTest):
+class TestIMolecule:
     def setUp(self):
         coords = [
             [0, 0, 0],
@@ -2327,7 +2327,7 @@ def test_to_file_alias(self):
         assert os.path.isfile(out_path)
 
 
-class TestMolecule(PymatgenTest):
+class TestMolecule:
     def setUp(self):
         coords = [
             [0, 0, 0],
diff --git a/tests/core/test_surface.py b/tests/core/test_surface.py
index 0527fc671b0..ccc09906bbe 100644
--- a/tests/core/test_surface.py
+++ b/tests/core/test_surface.py
@@ -24,12 +24,12 @@
 )
 from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
 from pymatgen.symmetry.groups import SpaceGroup
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 PMG_CORE_DIR = os.path.dirname(pymatgen.core.__file__)
 
 
-class TestSlab(PymatgenTest):
+class TestSlab:
     def setUp(self):
         zno1 = Structure.from_file(f"{TEST_FILES_DIR}/surfaces/ZnO-wz.cif", primitive=False)
         zno55 = SlabGenerator(zno1, [1, 0, 0], 5, 5, lll_reduce=False, center_slab=False).get_slab()
@@ -346,7 +346,7 @@ def test_as_dict(self):
         assert slab == Slab.from_dict(d)
 
 
-class TestSlabGenerator(PymatgenTest):
+class TestSlabGenerator:
     def setUp(self):
         lattice = Lattice.cubic(3.010)
         frac_coords = [
@@ -634,7 +634,7 @@ def test_bonds_broken(self):
         assert slabs[1].energy, 6.0
 
 
-class ReconstructionGeneratorTests(PymatgenTest):
+class ReconstructionGeneratorTests:
     def setUp(self):
         lattice = Lattice.cubic(3.51)
         species = ["Ni"]
@@ -723,7 +723,7 @@ def test_previous_reconstructions(self):
             assert any(len(match.group_structures([struct, slab])) == 1 for slab in slabs)
 
 
-class TestMillerIndexFinder(PymatgenTest):
+class TestMillerIndexFinder:
     def setUp(self):
         self.cscl = Structure.from_spacegroup("Pm-3m", Lattice.cubic(4.2), ["Cs", "Cl"], [[0, 0, 0], [0.5, 0.5, 0.5]])
         self.Fe = Structure.from_spacegroup("Im-3m", Lattice.cubic(2.82), ["Fe"], [[0, 0, 0]])
diff --git a/tests/core/test_tensors.py b/tests/core/test_tensors.py
index 1c840dcfa2b..1c78a299ed9 100644
--- a/tests/core/test_tensors.py
+++ b/tests/core/test_tensors.py
@@ -11,10 +11,10 @@
 from pymatgen.core.operations import SymmOp
 from pymatgen.core.tensors import SquareTensor, Tensor, TensorCollection, TensorMapping, itertools, symmetry_reduce
 from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 
-class TestTensor(PymatgenTest):
+class TestTensor:
     def setUp(self):
         rng = np.random.default_rng()
 
@@ -379,7 +379,7 @@ def test_round(self):
         assert isinstance(rounded, Tensor)
 
 
-class TestTensorCollection(PymatgenTest):
+class TestTensorCollection:
     def setUp(self):
         self.seq_tc = list(np.arange(4 * 3**3).reshape((4, 3, 3, 3)))
         self.seq_tc = TensorCollection(self.seq_tc)
@@ -472,7 +472,7 @@ def test_serialization(self):
             assert_allclose(t, t_new)
 
 
-class TestSquareTensor(PymatgenTest):
+class TestSquareTensor:
     def setUp(self):
         self.rand_sqtensor = SquareTensor(np.random.default_rng().standard_normal((3, 3)))
         self.symm_sqtensor = SquareTensor([[0.1, 0.3, 0.4], [0.3, 0.5, 0.2], [0.4, 0.2, 0.6]])
diff --git a/tests/core/test_trajectory.py b/tests/core/test_trajectory.py
index cac745a8a75..2cb7baae889 100644
--- a/tests/core/test_trajectory.py
+++ b/tests/core/test_trajectory.py
@@ -12,12 +12,12 @@
 from pymatgen.core.trajectory import Trajectory
 from pymatgen.io.qchem.outputs import QCOutput
 from pymatgen.io.vasp.outputs import Xdatcar
-from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/core/trajectory"
 
 
-class TestTrajectory(PymatgenTest):
+class TestTrajectory:
     def setUp(self):
         xdatcar = Xdatcar(f"{VASP_OUT_DIR}/XDATCAR_traj")
         self.traj = Trajectory.from_file(f"{VASP_OUT_DIR}/XDATCAR_traj")
diff --git a/tests/core/test_units.py b/tests/core/test_units.py
index 88e06d92517..1f3c7f2ac5b 100644
--- a/tests/core/test_units.py
+++ b/tests/core/test_units.py
@@ -26,7 +26,6 @@
     eV_to_Ha,
     unitized,
 )
-from pymatgen.util.testing import PymatgenTest
 
 
 def test_unit_conversions():
@@ -37,7 +36,7 @@ def test_unit_conversions():
     assert amu_to_kg == approx(1.66053906660e-27)
 
 
-class TestUnit(PymatgenTest):
+class TestUnit:
     def test_init(self):
         u1 = Unit((("m", 1), ("s", -1)))
         assert str(u1) == "m s^-1"
@@ -53,7 +52,7 @@ def test_init(self):
         assert str(newton * Unit("m")) == "N m"
 
 
-class TestFloatWithUnit(PymatgenTest):
+class TestFloatWithUnit:
     def test_energy(self):
         a = Energy(1.1, "eV")
         b = a.to("Ha")
@@ -185,7 +184,7 @@ def test_neg(self):
         assert FloatWithUnit(-5, "MPa") == -x
 
 
-class TestArrayWithUnit(PymatgenTest):
+class TestArrayWithUnit:
     def test_energy(self):
         """Similar to TestFloatWithUnit.test_energy.
         Check whether EnergyArray and FloatWithUnit have same behavior.
@@ -293,7 +292,7 @@ def test_as_base_units(self):
         assert_array_equal(ArrayWithUnit([5000000, 10000000], "Pa"), pressure_arr.as_base_units)
 
 
-class TestDataPersistence(PymatgenTest):
+class TestDataPersistence:
     def test_pickle(self):
         """Test whether FloatWithUnit and ArrayWithUnit support pickle."""
         for cls in [FloatWithUnit, ArrayWithUnit]:
diff --git a/tests/core/test_xcfunc.py b/tests/core/test_xcfunc.py
index 94627874bab..fd4c15e0d76 100644
--- a/tests/core/test_xcfunc.py
+++ b/tests/core/test_xcfunc.py
@@ -3,10 +3,9 @@
 import pytest
 
 from pymatgen.core.xcfunc import XcFunc
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestLibxcFunc(PymatgenTest):
+class TestLibxcFunc:
     def setUp(self) -> None:
         self.ixc_11 = XcFunc.from_abinit_ixc(11)
 
diff --git a/tests/electronic_structure/test_bandstructure.py b/tests/electronic_structure/test_bandstructure.py
index c5de50385ce..2cacd115159 100644
--- a/tests/electronic_structure/test_bandstructure.py
+++ b/tests/electronic_structure/test_bandstructure.py
@@ -20,7 +20,7 @@
 from pymatgen.electronic_structure.core import Orbital, Spin
 from pymatgen.electronic_structure.plotter import BSPlotterProjected
 from pymatgen.io.vasp import BSVasprun
-from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/electronic_structure/bandstructure"
 
@@ -68,7 +68,7 @@ def test_from_dict(self):
         assert kpoint.label == "X"
 
 
-class TestBandStructureSymmLine(PymatgenTest):
+class TestBandStructureSymmLine:
     def setUp(self):
         self.bs: BandStructureSymmLine = loadfn(f"{TEST_DIR}/Cu2O_361_bandstructure.json")
         self.bs2: BandStructureSymmLine = loadfn(f"{TEST_DIR}/CaO_2605_bandstructure.json")
@@ -258,7 +258,7 @@ def test_apply_scissor_spin_polarized(self):
         assert bs_scissored.efermi != approx(orig_efermi)
 
 
-class TestReconstructBandStructure(PymatgenTest):
+class TestReconstructBandStructure:
     def setUp(self):
         self.bs_cu: BandStructureSymmLine = loadfn(f"{TEST_DIR}/Cu_30_bandstructure.json")
         self.bs_cu2: BandStructureSymmLine = loadfn(f"{TEST_DIR}/Cu_30_bandstructure.json")
@@ -277,7 +277,7 @@ def test_vasprun_bs(self):
         bs.get_projection_on_elements()
 
 
-class TestLobsterBandStructureSymmLine(PymatgenTest):
+class TestLobsterBandStructureSymmLine:
     def setUp(self):
         with open(
             f"{TEST_FILES_DIR}/electronic_structure/cohp/Fatband_SiO2/Test_p/lobster_band_structure_spin.json",
diff --git a/tests/electronic_structure/test_cohp.py b/tests/electronic_structure/test_cohp.py
index 16f0ce2ca34..1da7a34b55f 100644
--- a/tests/electronic_structure/test_cohp.py
+++ b/tests/electronic_structure/test_cohp.py
@@ -15,7 +15,7 @@
     get_integrated_cohp_in_energy_range,
 )
 from pymatgen.electronic_structure.core import Orbital, Spin
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/electronic_structure/cohp"
 
@@ -797,7 +797,7 @@ def test_extremum_icohpvalue(self):
         assert self.icoopcollection_Fe.extremum_icohpvalue(summed_spin_channels=False, spin=Spin.down) == -0.05756
 
 
-class TestCompleteCohp(PymatgenTest):
+class TestCompleteCohp:
     def setUp(self):
         filepath = f"{TEST_DIR}/complete_cohp_lobster.json"
         with open(filepath) as file:
diff --git a/tests/electronic_structure/test_dos.py b/tests/electronic_structure/test_dos.py
index a7c8dec41b1..229738439c0 100644
--- a/tests/electronic_structure/test_dos.py
+++ b/tests/electronic_structure/test_dos.py
@@ -14,7 +14,7 @@
 from pymatgen.core import Element, Structure
 from pymatgen.electronic_structure.core import Orbital, OrbitalType, Spin
 from pymatgen.electronic_structure.dos import DOS, CompleteDos, FermiDos, LobsterCompleteDos
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/electronic_structure/dos"
 
@@ -323,7 +323,7 @@ def test_dos_fp_exceptions(self):
             self.dos.get_dos_fp_similarity(dos_fp, dos_fp2, col=1, metric=metric, normalize=False)
 
 
-class TestDOS(PymatgenTest):
+class TestDOS:
     def setUp(self):
         with open(f"{TEST_DIR}/complete_dos.json") as file:
             dct = json.load(file)
diff --git a/tests/electronic_structure/test_plotter.py b/tests/electronic_structure/test_plotter.py
index 59763e9ea59..2e80564a90c 100644
--- a/tests/electronic_structure/test_plotter.py
+++ b/tests/electronic_structure/test_plotter.py
@@ -30,14 +30,14 @@
     plot_ellipsoid,
 )
 from pymatgen.io.vasp import Vasprun
-from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR
 
 BAND_TEST_DIR = f"{TEST_FILES_DIR}/electronic_structure/bandstructure"
 
 rc("text", usetex=False)  # Disabling latex is needed for this test to work.
 
 
-class TestDosPlotter(PymatgenTest):
+class TestDosPlotter:
     def setUp(self):
         with open(f"{BAND_TEST_DIR}/../dos/complete_dos.json") as file:
             self.dos = CompleteDos.from_dict(json.load(file))
@@ -91,7 +91,7 @@ def get_plot_attributes(ax: plt.Axes):
         }
 
 
-class TestBSPlotter(PymatgenTest):
+class TestBSPlotter:
     def setUp(self):
         with open(f"{BAND_TEST_DIR}/CaO_2605_bandstructure.json") as file:
             dct = json.loads(file.read())
@@ -444,7 +444,7 @@ def test_plot_zt_temp(self):
         plt.close()
 
 
-class TestCohpPlotter(PymatgenTest):
+class TestCohpPlotter:
     def setUp(self):
         path = f"{TEST_FILES_DIR}/electronic_structure/cohp/complete_cohp_lobster.json"
         with open(path) as file:
diff --git a/tests/entries/test_entry_tools.py b/tests/entries/test_entry_tools.py
index 73d2d721d7b..3731857f98b 100644
--- a/tests/entries/test_entry_tools.py
+++ b/tests/entries/test_entry_tools.py
@@ -9,12 +9,12 @@
 from pymatgen.core import Element
 from pymatgen.entries.computed_entries import ComputedEntry
 from pymatgen.entries.entry_tools import EntrySet, group_entries_by_composition, group_entries_by_structure
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/entries"
 
 
-class TestFunc(PymatgenTest):
+class TestFunc:
     def test_group_entries_by_structure(self):
         entries = loadfn(f"{TEST_DIR}/TiO2_entries.json")
         groups = group_entries_by_structure(entries)
@@ -49,7 +49,7 @@ def test_group_entries_by_composition(self):
             assert group == sorted(group, key=lambda e: e.energy_per_atom)
 
 
-class TestEntrySet(PymatgenTest):
+class TestEntrySet:
     def setUp(self):
         entries = loadfn(f"{TEST_DIR}/Li-Fe-P-O_entries.json")
         self.entry_set = EntrySet(entries)
diff --git a/tests/ext/test_matproj.py b/tests/ext/test_matproj.py
index 18558a41525..0f0395577e0 100644
--- a/tests/ext/test_matproj.py
+++ b/tests/ext/test_matproj.py
@@ -23,7 +23,7 @@
 from pymatgen.ext.matproj_legacy import MPRestError, TaskType, _MPResterLegacy
 from pymatgen.phonon.bandstructure import PhononBandStructureSymmLine
 from pymatgen.phonon.dos import CompletePhononDos
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 PMG_MAPI_KEY = SETTINGS.get("PMG_MAPI_KEY", "")
 if (10 < len(PMG_MAPI_KEY) <= 20) and "PMG_MAPI_KEY" in SETTINGS:
@@ -48,7 +48,7 @@
     not 10 < len(PMG_MAPI_KEY) <= 20,
     reason="Legacy PMG_MAPI_KEY environment variable not set.",
 )
-class TestMPResterOld(PymatgenTest):
+class TestMPResterOld:
     def setUp(self):
         self.rester = _MPResterLegacy()
 
@@ -528,7 +528,7 @@ def test_api_key_is_none(self):
     not len(PMG_MAPI_KEY) > 20,
     reason="PMG_MAPI_KEY environment variable not set.",
 )
-class TestMPResterNewBasic(PymatgenTest):
+class TestMPResterNewBasic:
     def setUp(self):
         self.rester = _MPResterBasic()
 
diff --git a/tests/ext/test_optimade.py b/tests/ext/test_optimade.py
index e2710ddeaff..4a81116c5ce 100644
--- a/tests/ext/test_optimade.py
+++ b/tests/ext/test_optimade.py
@@ -4,7 +4,6 @@
 import requests
 
 from pymatgen.ext.optimade import OptimadeRester
-from pymatgen.util.testing import PymatgenTest
 
 try:
     # 403 is returned when server detects bot-like behavior
@@ -36,7 +35,7 @@
     mc2d_down = True
 
 
-class TestOptimade(PymatgenTest):
+class TestOptimade:
     @pytest.mark.skipif(mp_website_down, reason="MP OPTIMADE is down.")
     def test_get_structures_mp(self):
         with OptimadeRester("mp") as optimade:
diff --git a/tests/io/abinit/test_abiobjects.py b/tests/io/abinit/test_abiobjects.py
index ad38c49dafe..03b90aefe4b 100644
--- a/tests/io/abinit/test_abiobjects.py
+++ b/tests/io/abinit/test_abiobjects.py
@@ -19,10 +19,10 @@
     species_by_znucl,
     structure_to_abivars,
 )
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 
-class TestLatticeFromAbivars(PymatgenTest):
+class TestLatticeFromAbivars:
     def test_rprim_acell(self):
         l1 = lattice_from_abivars(acell=3 * [10], rprim=np.eye(3))
         assert l1.volume == approx(bohr_to_ang**3 * 1000)
@@ -108,7 +108,7 @@ def test_znucl_typat(self):
             structure_to_abivars(gan, enforce_znucl=enforce_znucl, enforce_typat=None)
 
 
-class TestSpinMode(PymatgenTest):
+class TestSpinMode:
     def test_base(self):
         polarized = SpinMode.as_spinmode("polarized")
         other_polarized = SpinMode.as_spinmode("polarized")
@@ -128,7 +128,7 @@ def test_base(self):
         self.assert_msonable(unpolarized)
 
 
-class TestSmearing(PymatgenTest):
+class TestSmearing:
     def test_base(self):
         fd1ev = Smearing.as_smearing("fermi_dirac:1 eV")
         fd1ev.to_abivars()
@@ -156,7 +156,7 @@ def test_base(self):
         self.assert_msonable(fd1ev)
 
 
-class TestElectronsAlgorithm(PymatgenTest):
+class TestElectronsAlgorithm:
     def test_base(self):
         algo = ElectronsAlgorithm(nstep=70)
         _ = algo.to_abivars()
@@ -168,7 +168,7 @@ def test_base(self):
         self.assert_msonable(algo)
 
 
-class TestElectrons(PymatgenTest):
+class TestElectrons:
     def test_base(self):
         default_electrons = Electrons()
         assert default_electrons.nsppol == 2
@@ -195,7 +195,7 @@ def test_base(self):
         self.assert_msonable(custom_electrons)
 
 
-class TestKSampling(PymatgenTest):
+class TestKSampling:
     def test_base(self):
         monkhorst = KSampling.monkhorst((3, 3, 3), (0.5, 0.5, 0.5), 0, use_symmetries=False, use_time_reversal=False)
         gamma_centered = KSampling.gamma_centered((3, 3, 3), use_symmetries=False, use_time_reversal=False)
@@ -207,7 +207,7 @@ def test_base(self):
         self.assert_msonable(gamma_centered)
 
 
-class TestRelaxation(PymatgenTest):
+class TestRelaxation:
     def test_base(self):
         atoms_and_cell = RelaxationMethod.atoms_and_cell()
         atoms_only = RelaxationMethod.atoms_only()
@@ -227,7 +227,7 @@ def test_base(self):
         self.assert_msonable(atoms_only)
 
 
-class TestPPModel(PymatgenTest):
+class TestPPModel:
     def test_base(self):
         godby = PPModel.as_ppmodel("godby:12 eV")
         godby.to_abivars()
diff --git a/tests/io/abinit/test_inputs.py b/tests/io/abinit/test_inputs.py
index 762ea2acad8..abcb129f4fb 100644
--- a/tests/io/abinit/test_inputs.py
+++ b/tests/io/abinit/test_inputs.py
@@ -18,7 +18,7 @@
     ion_ioncell_relax_input,
     num_valence_electrons,
 )
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/abinit"
 
@@ -33,7 +33,7 @@ def abiref_files(*filenames):
     return [f"{TEST_DIR}/{file}" for file in filenames]
 
 
-class TestAbinitInput(PymatgenTest):
+class TestAbinitInput:
     """Unit tests for BasicAbinitInput."""
 
     def test_api(self):
@@ -168,7 +168,7 @@ def test_helper_functions(self):
         assert len(inp["kptbounds"]) == 12
 
 
-class TestMultiDataset(PymatgenTest):
+class TestMultiDataset:
     """Unit tests for BasicMultiDataset."""
 
     def test_api(self):
@@ -251,7 +251,7 @@ def test_api(self):
         self.serialize_with_pickle(multi, test_eq=False)
 
 
-class TestShiftMode(PymatgenTest):
+class TestShiftMode:
     def test_shiftmode(self):
         gamma = ShiftMode.GammaCentered
         assert ShiftMode.from_object("G") == gamma
@@ -260,7 +260,7 @@ def test_shiftmode(self):
             ShiftMode.from_object({})
 
 
-class TestFactory(PymatgenTest):
+class TestFactory:
     def setUp(self):
         # Si ebands
         self.si_structure = Structure.from_file(abiref_file("si.cif"))
diff --git a/tests/io/abinit/test_netcdf.py b/tests/io/abinit/test_netcdf.py
index b4b2ffa68c1..2006d5bdbb0 100644
--- a/tests/io/abinit/test_netcdf.py
+++ b/tests/io/abinit/test_netcdf.py
@@ -11,7 +11,7 @@
 from pymatgen.core.structure import Structure
 from pymatgen.io.abinit import EtsfReader
 from pymatgen.io.abinit.netcdf import AbinitHeader
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 try:
     import netCDF4
@@ -21,7 +21,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/io/abinit"
 
 
-class TestEtsfReader(PymatgenTest):
+class TestEtsfReader:
     def setUp(self):
         formulas = ["Si2"]
         self.GSR_paths = dct = {}
@@ -117,7 +117,7 @@ def test_read_fe(self):
                     assert structure.site_properties["magmom"] == ref_magmom_noncollinear
 
 
-class TestAbinitHeader(PymatgenTest):
+class TestAbinitHeader:
     def test_api(self):
         head = AbinitHeader(foo=1, bar=2)
         assert head.foo == 1
diff --git a/tests/io/abinit/test_pseudos.py b/tests/io/abinit/test_pseudos.py
index 8cd9bace814..7d874908c0d 100644
--- a/tests/io/abinit/test_pseudos.py
+++ b/tests/io/abinit/test_pseudos.py
@@ -9,12 +9,12 @@
 from pytest import approx
 
 from pymatgen.io.abinit.pseudos import Pseudo, PseudoTable
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/abinit"
 
 
-class TestPseudo(PymatgenTest):
+class TestPseudo:
     def setUp(self):
         nc_pseudo_fnames = defaultdict(list)
         nc_pseudo_fnames["Si"] = [f"{TEST_DIR}/{file}" for file in ("14si.pspnc", "14si.4.hgh", "14-Si.LDA.fhi")]
@@ -198,7 +198,7 @@ def test_oncvpsp_pseudo_fr(self):
         assert pb.supports_soc
 
 
-class TestPseudoTable(PymatgenTest):
+class TestPseudoTable:
     def test_methods(self):
         """Test PseudoTable methods."""
         table = PseudoTable([f"{TEST_DIR}/{file}" for file in ("14si.pspnc", "14si.4.hgh", "14-Si.LDA.fhi")])
diff --git a/tests/io/cp2k/test_inputs.py b/tests/io/cp2k/test_inputs.py
index ec0b772c617..7da41494b62 100644
--- a/tests/io/cp2k/test_inputs.py
+++ b/tests/io/cp2k/test_inputs.py
@@ -22,7 +22,7 @@
     Section,
     SectionList,
 )
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/cp2k"
 
@@ -41,7 +41,7 @@
 """
 
 
-class TestBasis(PymatgenTest):
+class TestBasis:
     def test_basis_info(self):
         # Ensure basis metadata can be read from string
         basis_info = BasisInfo.from_str("cc-pc-DZVP-MOLOPT-q1-SCAN")
@@ -92,7 +92,7 @@ def test_basis(self):
         mol_opt.info.admm = False
 
 
-class TestPotential(PymatgenTest):
+class TestPotential:
     all_hydrogen_str = """
 H ALLELECTRON ALL
     1    0    0
@@ -144,7 +144,7 @@ def test_potentials(self):
         assert kw.values[0] == "ALL"
 
 
-class TestCp2kInput(PymatgenTest):
+class TestCp2kInput:
     si_struct = Structure(
         lattice=[
             [0, 2.734364, 2.734364],
@@ -268,7 +268,7 @@ def test_mongo(self):
         assert cp2k_input.check("global/subsec2")
 
 
-class TestDataFile(PymatgenTest):
+class TestDataFile:
     def test_data_file(self):
         # make temp file with BASIS_FILE_STR
         data_file = self.tmp_path / "data-file"
diff --git a/tests/io/cp2k/test_sets.py b/tests/io/cp2k/test_sets.py
index e2c74bc31a6..943facb4b87 100644
--- a/tests/io/cp2k/test_sets.py
+++ b/tests/io/cp2k/test_sets.py
@@ -6,7 +6,7 @@
 
 from pymatgen.core.structure import Molecule, Structure
 from pymatgen.io.cp2k.sets import SETTINGS, Cp2kValidationError, DftSet, GaussianTypeOrbitalBasisSet, GthPotential
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 CP2K_TEST_DIR = f"{TEST_FILES_DIR}/io/cp2k"
 
@@ -46,7 +46,7 @@
 }
 
 
-class TestDftSet(PymatgenTest):
+class TestDftSet:
     def test_dft_set(self) -> None:
         """Test various DFT set configurations."""
         SETTINGS["PMG_CP2K_DATA_DIR"] = CP2K_TEST_DIR
diff --git a/tests/io/exciting/test_inputs.py b/tests/io/exciting/test_inputs.py
index ccbac253944..e3b134f8429 100644
--- a/tests/io/exciting/test_inputs.py
+++ b/tests/io/exciting/test_inputs.py
@@ -6,7 +6,7 @@
 
 from pymatgen.core import Lattice, Structure
 from pymatgen.io.exciting import ExcitingInput
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Christian Vorwerk"
 __copyright__ = "Copyright 2016"
@@ -19,7 +19,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/io/exciting"
 
 
-class TestExcitingInput(PymatgenTest):
+class TestExcitingInput:
     def test_fromfile(self):
         # Test for the import of a structure directly from an exciting
         # input file
diff --git a/tests/io/feff/test_sets.py b/tests/io/feff/test_sets.py
index e57e560996c..8dae8b7e546 100644
--- a/tests/io/feff/test_sets.py
+++ b/tests/io/feff/test_sets.py
@@ -9,12 +9,12 @@
 from pymatgen.core.structure import Lattice, Molecule, Structure
 from pymatgen.io.feff.inputs import Atoms, Header, Potential, Tags
 from pymatgen.io.feff.sets import FEFFDictSet, MPELNESSet, MPEXAFSSet, MPXANESSet
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 FEFF_TEST_DIR = f"{TEST_FILES_DIR}/io/feff"
 
 
-class TestFeffInputSet(PymatgenTest):
+class TestFeffInputSet:
     @classmethod
     def setUpClass(cls):
         cls.header_string = """* This FEFF.inp file generated by pymatgen
diff --git a/tests/io/lammps/test_data.py b/tests/io/lammps/test_data.py
index 3be78db967c..a121b7ef680 100644
--- a/tests/io/lammps/test_data.py
+++ b/tests/io/lammps/test_data.py
@@ -14,12 +14,12 @@
 
 from pymatgen.core import Element, Lattice, Molecule, Structure
 from pymatgen.io.lammps.data import CombinedData, ForceField, LammpsBox, LammpsData, Topology, lattice_2_lmpbox
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/lammps"
 
 
-class TestLammpsBox(PymatgenTest):
+class TestLammpsBox:
     @classmethod
     def setUpClass(cls):
         cls.peptide = LammpsBox(
@@ -73,7 +73,7 @@ def test_to_lattice(self):
         )
 
 
-class TestLammpsData(PymatgenTest):
+class TestLammpsData:
     @classmethod
     def setUpClass(cls):
         cls.peptide = LammpsData.from_file(filename=f"{TEST_DIR}/data.peptide")
@@ -665,7 +665,7 @@ def test_from_bonding(self):
         assert "Dihedrals" not in topo_etoh2.topologies
 
 
-class TestForceField(PymatgenTest):
+class TestForceField:
     @classmethod
     def setUpClass(cls):
         mass_info = [
diff --git a/tests/io/lammps/test_generators.py b/tests/io/lammps/test_generators.py
index d19eddbf8df..3db0fae78d8 100644
--- a/tests/io/lammps/test_generators.py
+++ b/tests/io/lammps/test_generators.py
@@ -3,12 +3,12 @@
 from pymatgen.core.structure import Structure
 from pymatgen.io.lammps.data import LammpsData
 from pymatgen.io.lammps.generators import LammpsMinimization
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/lammps"
 
 
-class TestLammpsMinimization(PymatgenTest):
+class TestLammpsMinimization:
     @classmethod
     def setUpClass(cls):
         cls.filename = f"{TEST_DIR}/lgps.in"
diff --git a/tests/io/lammps/test_inputs.py b/tests/io/lammps/test_inputs.py
index 15f8ef3fac4..fb25b788732 100644
--- a/tests/io/lammps/test_inputs.py
+++ b/tests/io/lammps/test_inputs.py
@@ -11,12 +11,12 @@
 from pymatgen.core.structure import Structure
 from pymatgen.io.lammps.data import LammpsData
 from pymatgen.io.lammps.inputs import LammpsInputFile, LammpsRun, LammpsTemplateGen, write_lammps_inputs
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/lammps"
 
 
-class TestLammpsInputFile(PymatgenTest):
+class TestLammpsInputFile:
     @classmethod
     def setUpClass(cls):
         cls.filename = f"{TEST_DIR}/lgps.in"
@@ -640,7 +640,7 @@ def test_add_comment(self):
         ]
 
 
-class TestLammpsRun(PymatgenTest):
+class TestLammpsRun:
     def test_md(self):
         struct = Structure.from_spacegroup(225, Lattice.cubic(3.62126), ["Cu"], [[0, 0, 0]])
         ld = LammpsData.from_structure(struct, atom_style="atomic")
@@ -690,7 +690,7 @@ def test_md(self):
         assert os.path.isfile(f"{self.tmp_path}/md/md.data")
 
 
-class TestFunc(PymatgenTest):
+class TestFunc:
     @pytest.mark.filterwarnings("ignore:write_lammps_inputs is deprecated")
     def test_write_lammps_inputs(self):
         # script template
@@ -727,7 +727,7 @@ def test_write_lammps_inputs(self):
             pd.testing.assert_frame_equal(obj_read.atoms, obj.atoms)
 
 
-class TestLammpsTemplateGen(PymatgenTest):
+class TestLammpsTemplateGen:
     def test_write_inputs(self):
         # simple script without data file
         lis = LammpsTemplateGen().get_input_set(
diff --git a/tests/io/lobster/test_inputs.py b/tests/io/lobster/test_inputs.py
index 59960d5970f..72feec95f87 100644
--- a/tests/io/lobster/test_inputs.py
+++ b/tests/io/lobster/test_inputs.py
@@ -8,7 +8,7 @@
 from pymatgen.io.lobster import Lobsterin
 from pymatgen.io.lobster.inputs import get_all_possible_basis_combinations
 from pymatgen.io.vasp.inputs import Incar, Kpoints, Potcar
-from pymatgen.util.testing import FAKE_POTCAR_DIR, TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR, PymatgenTest
+from pymatgen.util.testing import FAKE_POTCAR_DIR, TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/electronic_structure/cohp"
 
@@ -19,7 +19,7 @@
 __date__ = "Dec 10, 2017"
 
 
-class TestLobsterin(PymatgenTest):
+class TestLobsterin:
     def setUp(self):
         self.Lobsterin = Lobsterin.from_file(f"{TEST_DIR}/lobsterin.1")
         self.Lobsterin2 = Lobsterin.from_file(f"{TEST_DIR}/lobsterin.2")
@@ -579,7 +579,7 @@ def test_as_from_dict(self):
         new_lobsterin.to_json()
 
 
-class TestUtils(PymatgenTest):
+class TestUtils:
     def test_get_all_possible_basis_combinations(self):
         # this basis is just for testing (not correct)
         min_basis = ["Li 1s 2s ", "Na 1s 2s", "Si 1s 2s"]
diff --git a/tests/io/lobster/test_outputs.py b/tests/io/lobster/test_outputs.py
index 4dac8c4a01b..ac9ff882d82 100644
--- a/tests/io/lobster/test_outputs.py
+++ b/tests/io/lobster/test_outputs.py
@@ -31,7 +31,7 @@
     Wavefunction,
 )
 from pymatgen.io.vasp import Vasprun
-from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/electronic_structure/cohp"
 
@@ -42,7 +42,7 @@
 __date__ = "Dec 10, 2017"
 
 
-class TestBwdf(PymatgenTest):
+class TestBwdf:
     def setUp(self):
         self.bwdf_coop = Bwdf(filename=f"{TEST_DIR}/BWDF.lobster.AlN.gz")
         self.bwdf_cohp = Bwdf(filename=f"{TEST_DIR}/BWDFCOHP.lobster.NaCl.gz")
@@ -57,7 +57,7 @@ def test_attributes(self):
         assert self.bwdf_cohp.bwdf[Spin.up][103] == approx(-0.01392, abs=1e-4)
 
 
-class TestCohpcar(PymatgenTest):
+class TestCohpcar:
     def setUp(self):
         self.cohp_bise = Cohpcar(filename=f"{TEST_DIR}/COHPCAR.lobster.BiSe.gz")
         self.coop_bise = Cohpcar(
@@ -637,7 +637,7 @@ def test_is_spin_polarized(self):
         assert not self.DOSCAR_nonspin_pol.is_spin_polarized
 
 
-class TestCharge(PymatgenTest):
+class TestCharge:
     def setUp(self):
         self.charge2 = Charge(filename=f"{TEST_DIR}/CHARGE.lobster.MnO")
         # gzipped file
@@ -716,7 +716,7 @@ def test_msonable(self):
             assert getattr(charge_from_dict, attr_name) == attr_value
 
 
-class TestLobsterout(PymatgenTest):
+class TestLobsterout:
     def setUp(self):
         self.lobsterout_normal = Lobsterout(filename=f"{TEST_DIR}/lobsterout.normal")
         # make sure .gz files are also read correctly
@@ -1245,7 +1245,7 @@ def test_msonable(self):
             Lobsterout(filename=None, invalid="val")
 
 
-class TestFatband(PymatgenTest):
+class TestFatband:
     def setUp(self):
         self.structure = Vasprun(
             filename=f"{TEST_DIR}/Fatband_SiO2/Test_p_x/vasprun.xml",
@@ -2204,7 +2204,7 @@ def test_ncicobilist(self):
         )
 
 
-class TestWavefunction(PymatgenTest):
+class TestWavefunction:
     def test_parse_file(self):
         grid, points, real, imaginary, distance = Wavefunction._parse_file(
             f"{TEST_DIR}/LCAOWaveFunctionAfterLSO1PlotOfSpin1Kpoint1band1.gz"
@@ -2272,7 +2272,7 @@ def test_write_file(self):
         assert os.path.isfile(density_wavecar_path)
 
 
-class TestSitePotentials(PymatgenTest):
+class TestSitePotentials:
     def setUp(self) -> None:
         self.sitepotential = SitePotential(filename=f"{TEST_DIR}/SitePotentials.lobster.perovskite")
 
@@ -2323,7 +2323,7 @@ def test_msonable(self):
             assert getattr(sitepotential_from_dict, attr_name) == attr_value
 
 
-class TestMadelungEnergies(PymatgenTest):
+class TestMadelungEnergies:
     def setUp(self) -> None:
         self.madelungenergies = MadelungEnergies(filename=f"{TEST_DIR}/MadelungEnergies.lobster.perovskite")
 
@@ -2340,7 +2340,7 @@ def test_msonable(self):
             assert getattr(madelung_from_dict, attr_name) == attr_value
 
 
-class TestLobsterMatrices(PymatgenTest):
+class TestLobsterMatrices:
     def setUp(self) -> None:
         self.hamilton_matrices = LobsterMatrices(
             filename=f"{TEST_DIR}/Na_hamiltonMatrices.lobster.gz", e_fermi=-2.79650354
@@ -2490,7 +2490,7 @@ def test_raises(self):
             self.hamilton_matrices = LobsterMatrices(filename=f"{TEST_DIR}/hamiltonMatrices.lobster")
 
 
-class TestPolarization(PymatgenTest):
+class TestPolarization:
     def setUp(self) -> None:
         self.polarization = Polarization(filename=f"{TEST_DIR}/POLARIZATION.lobster.AlN.gz")
 
diff --git a/tests/io/pwmat/test_inputs.py b/tests/io/pwmat/test_inputs.py
index 7618e7ecdf6..8e21dc0428f 100644
--- a/tests/io/pwmat/test_inputs.py
+++ b/tests/io/pwmat/test_inputs.py
@@ -18,7 +18,7 @@
     LineLocator,
     ListLocator,
 )
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/pwmat"
 
@@ -43,7 +43,7 @@ def test_list_locator(exclusion: str, expected_idx: int):
     assert aim_idx == expected_idx
 
 
-class TestACstrExtractor(PymatgenTest):
+class TestACstrExtractor:
     def test_extract(self):
         filepath = f"{TEST_DIR}/atom.config"
         ac_extractor = ACExtractor(file_path=filepath)
@@ -60,7 +60,7 @@ def test_extract(self):
             assert ac_extractor.magmoms[idx] == ac_str_extractor.get_magmoms()[idx]
 
 
-class TestAtomConfig(PymatgenTest):
+class TestAtomConfig:
     def test_init(self):
         filepath = f"{TEST_DIR}/atom.config"
         structure = Structure.from_file(filepath)
@@ -82,7 +82,7 @@ def test_write_file(self):
         assert_allclose(atom_config.structure.lattice.abc, tmp_atom_config.structure.lattice.abc, 5)
 
 
-class TestGenKpt(PymatgenTest):
+class TestGenKpt:
     def test_from_structure(self):
         pytest.importorskip("seekpath")
         filepath = f"{TEST_DIR}/atom.config"
@@ -107,7 +107,7 @@ def test_write_file(self):
         assert gen_kpt.get_str() == tmp_gen_kpt_str
 
 
-class TestHighSymmetryPoint(PymatgenTest):
+class TestHighSymmetryPoint:
     def test_from_structure(self):
         pytest.importorskip("seekpath")
         filepath = f"{TEST_DIR}/atom.config"
diff --git a/tests/io/pwmat/test_outputs.py b/tests/io/pwmat/test_outputs.py
index b2a97f891fe..ea7d0150122 100644
--- a/tests/io/pwmat/test_outputs.py
+++ b/tests/io/pwmat/test_outputs.py
@@ -1,12 +1,12 @@
 from __future__ import annotations
 
 from pymatgen.io.pwmat.outputs import DosSpin, Movement, OutFermi, Report
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/pwmat"
 
 
-class TestMovement(PymatgenTest):
+class TestMovement:
     def test_init_and_properties(self):
         filepath = f"{TEST_DIR}/MOVEMENT.lzma"
         movement = Movement(filepath)
@@ -26,14 +26,14 @@ def test_init_and_properties(self):
         assert movement.ionic_steps[0]["e_tot"] == -357677.2281
 
 
-class TestOutFermi(PymatgenTest):
+class TestOutFermi:
     def test_init_and_properties(self):
         filepath = f"{TEST_DIR}/OUT.FERMI.lzma"
         out_fermi = OutFermi(filepath)
         assert out_fermi.e_fermi == -2.359
 
 
-class TestReport(PymatgenTest):
+class TestReport:
     def test_init_and_properties(self):
         filepath = f"{TEST_DIR}/REPORT"
         report = Report(filepath)
@@ -46,7 +46,7 @@ def test_init_and_properties(self):
         assert report.hsps == {}
 
 
-class TestDosSpin(PymatgenTest):
+class TestDosSpin:
     def test_init_and_properties(self):
         filepath = f"{TEST_DIR}/DOS.spinup_projected"
         dos_spin = DosSpin(filepath)
diff --git a/tests/io/qchem/test_inputs.py b/tests/io/qchem/test_inputs.py
index fe87a29a095..49737711af7 100644
--- a/tests/io/qchem/test_inputs.py
+++ b/tests/io/qchem/test_inputs.py
@@ -8,7 +8,7 @@
 from pymatgen.core.structure import Molecule
 from pymatgen.io.qchem.inputs import QCInput
 from pymatgen.io.qchem.sets import OptSet
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/qchem"
 
@@ -20,7 +20,7 @@
 __credits__ = "Xiaohui Qu"
 
 
-class TestQCInput(PymatgenTest):
+class TestQCInput:
     def test_molecule_template(self):
         species = ["C", "O"]
         coords = [
diff --git a/tests/io/qchem/test_outputs.py b/tests/io/qchem/test_outputs.py
index 22f681f8918..0c727a1bdce 100644
--- a/tests/io/qchem/test_outputs.py
+++ b/tests/io/qchem/test_outputs.py
@@ -17,7 +17,7 @@
     hessian_parser,
     orbital_coeffs_parser,
 )
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 try:
     from openbabel import openbabel
@@ -260,7 +260,7 @@
 }
 
 
-class TestQCOutput(PymatgenTest):
+class TestQCOutput:
     @staticmethod
     def generate_single_job_dict():
         """Used to generate test dictionary for single jobs."""
diff --git a/tests/io/qchem/test_sets.py b/tests/io/qchem/test_sets.py
index 9a677b02ab8..f969e5a1c78 100644
--- a/tests/io/qchem/test_sets.py
+++ b/tests/io/qchem/test_sets.py
@@ -14,7 +14,7 @@
     SinglePointSet,
     TransitionStateSet,
 )
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Samuel Blau, Brandon Wood, Shyam Dwaraknath, Evan Spotte-Smith, Ryan Kingsbury"
 __copyright__ = "Copyright 2018-2022, The Materials Project"
@@ -26,7 +26,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/io/qchem/new_qchem_files"
 
 
-class TestQChemDictSet(PymatgenTest):
+class TestQChemDictSet:
     def test_init(self):
         test_molecule = QCInput.from_file(f"{TEST_DIR}/pcm.qin").molecule
         test_dict_set = QChemDictSet(
@@ -469,7 +469,7 @@ def test_solvation_warnings(self):
             )
 
 
-class TestSinglePointSet(PymatgenTest):
+class TestSinglePointSet:
     def test_init(self):
         test_molecule = QCInput.from_file(f"{TEST_DIR}/pcm.qin").molecule
         test_sp_set = SinglePointSet(molecule=test_molecule)
@@ -671,7 +671,7 @@ def test_plots_init(self):
         assert test_sp_set.molecule == test_molecule
 
 
-class TestOptSet(PymatgenTest):
+class TestOptSet:
     def test_init(self):
         test_molecule = QCInput.from_file(f"{TEST_DIR}/pcm.qin").molecule
         test_opt_set = OptSet(molecule=test_molecule)
@@ -846,7 +846,7 @@ def test_v5_vs_v6(self):
         assert v6_opt_set_modified.geom_opt == ref_dict
 
 
-class TestTransitionStateSet(PymatgenTest):
+class TestTransitionStateSet:
     def test_init(self):
         test_molecule = QCInput.from_file(f"{TEST_DIR}/pcm.qin").molecule
         test_ts_set = TransitionStateSet(molecule=test_molecule)
@@ -927,7 +927,7 @@ def test_smd_init(self):
         assert test_ts_set.molecule == test_molecule
 
 
-class TestForceSet(PymatgenTest):
+class TestForceSet:
     def test_init(self):
         test_molecule = QCInput.from_file(f"{TEST_DIR}/pcm.qin").molecule
         test_forceset = ForceSet(molecule=test_molecule)
@@ -1004,7 +1004,7 @@ def test_smd_init(self):
         assert test_forceset.molecule == test_molecule
 
 
-class TestPESScanSet(PymatgenTest):
+class TestPESScanSet:
     def test_init(self):
         test_molecule = QCInput.from_file(f"{TEST_DIR}/pes_scan.qin").molecule
 
@@ -1097,7 +1097,7 @@ def test_smd_init(self):
         assert test_pes_scan.molecule == test_molecule
 
 
-class TestFreqSet(PymatgenTest):
+class TestFreqSet:
     def test_init(self):
         test_molecule = QCInput.from_file(f"{TEST_DIR}/pcm.qin").molecule
         test_freq_set = FreqSet(molecule=test_molecule)
diff --git a/tests/io/qchem/test_utils.py b/tests/io/qchem/test_utils.py
index 4ad091b8242..c12dc788063 100644
--- a/tests/io/qchem/test_utils.py
+++ b/tests/io/qchem/test_utils.py
@@ -6,7 +6,7 @@
 from monty.io import zopen
 
 from pymatgen.io.qchem.utils import lower_and_check_unique, process_parsed_hess
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Ryan Kingsbury, Samuel Blau"
 __copyright__ = "Copyright 2018-2022, The Materials Project"
@@ -15,7 +15,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/io/qchem/new_qchem_files"
 
 
-class TestUtil(PymatgenTest):
+class TestUtil:
     """test utils."""
 
     def test_lower_and_check_unique(self):
diff --git a/tests/io/test_adf.py b/tests/io/test_adf.py
index d3b6785320f..43d210e8a3e 100644
--- a/tests/io/test_adf.py
+++ b/tests/io/test_adf.py
@@ -4,7 +4,7 @@
 
 from pymatgen.core.structure import Molecule
 from pymatgen.io.adf import AdfInput, AdfKey, AdfOutput, AdfTask
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Xin Chen, chenxin13@mails.tsinghua.edu.cn"
 
@@ -242,7 +242,7 @@ def test_serialization(self):
 }
 
 
-class TestAdfInput(PymatgenTest):
+class TestAdfInput:
     def test_main(self):
         tmp_file = f"{self.tmp_path}/adf.temp"
         mol = Molecule.from_str(rhb18_xyz, "xyz")
diff --git a/tests/io/test_atat.py b/tests/io/test_atat.py
index a9562f92511..23c9ca9472e 100644
--- a/tests/io/test_atat.py
+++ b/tests/io/test_atat.py
@@ -5,12 +5,12 @@
 
 from pymatgen.core.structure import Structure
 from pymatgen.io.atat import Mcsqs
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/atat/mcsqs"
 
 
-class TestAtat(PymatgenTest):
+class TestAtat:
     def test_mcsqs_import(self):
         test_str = """1.000000 0.000000 0.000000
 0.000000 1.000000 0.000000
diff --git a/tests/io/test_cif.py b/tests/io/test_cif.py
index 690c67c302d..3dd01454bb9 100644
--- a/tests/io/test_cif.py
+++ b/tests/io/test_cif.py
@@ -9,7 +9,7 @@
 from pymatgen.electronic_structure.core import Magmom
 from pymatgen.io.cif import CifBlock, CifParser, CifWriter
 from pymatgen.symmetry.structure import SymmetrizedStructure
-from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR, VASP_IN_DIR
 
 try:
     import pybtex
@@ -20,7 +20,7 @@
 MCIF_TEST_DIR = f"{TEST_FILES_DIR}/io/cif/mcif"
 
 
-class TestCifBlock(PymatgenTest):
+class TestCifBlock:
     def test_to_str(self):
         with open(f"{TEST_FILES_DIR}/cif/Graphite.cif") as file:
             cif_str = file.read()
@@ -164,7 +164,7 @@ def test_long_loop(self):
         assert str(CifBlock(data, loops, "test")) == cif_str
 
 
-class TestCifIO(PymatgenTest):
+class TestCifIO:
     def test_cif_parser(self):
         parser = CifParser(f"{TEST_FILES_DIR}/cif/LiFePO4.cif")
         for struct in parser.parse_structures():
@@ -999,7 +999,7 @@ def test_cif_writer_site_properties(self):
         assert "O  O23  1  0.95662769  0.25000000  0.29286233  1  -1.0" in cif_str
 
 
-class TestMagCif(PymatgenTest):
+class TestMagCif:
     def setUp(self):
         self.mcif = CifParser(f"{MCIF_TEST_DIR}/magnetic.example.NiO.mcif")
         self.mcif_ncl = CifParser(f"{MCIF_TEST_DIR}/magnetic.ncl.example.GdB4.mcif")
diff --git a/tests/io/test_core.py b/tests/io/test_core.py
index bd4ad9ea7fa..77e6b410b96 100644
--- a/tests/io/test_core.py
+++ b/tests/io/test_core.py
@@ -10,7 +10,7 @@
 from pymatgen.core.structure import Structure
 from pymatgen.io.cif import CifParser, CifWriter
 from pymatgen.io.core import InputFile, InputSet
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 if TYPE_CHECKING:
     from typing_extensions import Self
@@ -44,7 +44,7 @@ def __str__(self):
         return f"{self.a}\n{self.b}"
 
 
-class TestInputFile(PymatgenTest):
+class TestInputFile:
     def test_file_io(self):
         with pytest.raises(FileNotFoundError, match="No such file or directory: 'fakepath.cif'"):
             StructInputFile.from_file("fakepath.cif")
@@ -64,7 +64,7 @@ def test_msonable(self):
         assert sif.structure == temp_sif.structure
 
 
-class TestInputSet(PymatgenTest):
+class TestInputSet:
     @classmethod
     def setUpClass(cls):
         cls.sif1 = StructInputFile.from_file(f"{TEST_FILES_DIR}/cif/Li.cif")
diff --git a/tests/io/test_lmto.py b/tests/io/test_lmto.py
index 1ddc8c2abcf..7a73dfa791b 100644
--- a/tests/io/test_lmto.py
+++ b/tests/io/test_lmto.py
@@ -10,7 +10,7 @@
 from pymatgen.electronic_structure.core import Spin
 from pymatgen.io.lmto import LMTOCopl, LMTOCtrl
 from pymatgen.util.num import round_to_sigfigs
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Marco Esters"
 __copyright__ = "Copyright 2017, The Materials Project"
@@ -23,7 +23,7 @@
 MODULE_DIR = os.path.dirname(os.path.abspath(__file__))
 
 
-class TestCtrl(PymatgenTest):
+class TestCtrl:
     def setUp(self):
         os.chdir(TEST_DIR)
         self.ref_bise = LMTOCtrl.from_file(filename="CTRL.BiSe")
@@ -47,7 +47,7 @@ def test_read_write(self):
         assert self.ref_bise.structure.matches(ctrl_file.structure)
 
 
-class TestCopl(PymatgenTest):
+class TestCopl:
     def setUp(self):
         os.chdir(TEST_DIR)
         self.copl_bise = LMTOCopl("COPL.BiSe")
diff --git a/tests/io/test_packmol.py b/tests/io/test_packmol.py
index c6d25953dcd..5c709436d83 100644
--- a/tests/io/test_packmol.py
+++ b/tests/io/test_packmol.py
@@ -10,7 +10,7 @@
 from pymatgen.analysis.molecule_matcher import MoleculeMatcher
 from pymatgen.core import Molecule
 from pymatgen.io.packmol import PackmolBoxGen
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/packmol"
 # error message is different in CI for unknown reasons (as of 2024-04-12)
@@ -48,7 +48,7 @@
 water = Molecule(water_atoms, water_coords)
 
 
-class TestPackmolSet(PymatgenTest):
+class TestPackmolSet:
     def test_packmol_with_molecule(self):
         """Test coords input as Molecule."""
         pw = PackmolBoxGen().get_input_set(
diff --git a/tests/io/test_phonopy.py b/tests/io/test_phonopy.py
index 802e43049e2..588a027adc3 100644
--- a/tests/io/test_phonopy.py
+++ b/tests/io/test_phonopy.py
@@ -42,7 +42,7 @@
 PHONON_DIR = f"{TEST_FILES_DIR}/phonon"
 
 
-class TestPhonopyParser(PymatgenTest):
+class TestPhonopyParser:
     def test_get_ph_bs(self):
         ph_bs = get_ph_bs_symm_line(f"{TEST_DIR}/NaCl_band.yaml", has_nac=True)
 
@@ -98,7 +98,7 @@ def test_get_complete_dos(self):
 
 
 @pytest.mark.skipif(Phonopy is None, reason="Phonopy not present")
-class TestStructureConversion(PymatgenTest):
+class TestStructureConversion:
     def test_structure_conversion(self):
         struct_pmg = PymatgenTest.get_structure("LiFePO4")
         # add magmoms to site_properties
@@ -126,7 +126,7 @@ def test_structure_conversion(self):
 
 
 @pytest.mark.skipif(Phonopy is None, reason="Phonopy not present")
-class TestGetDisplacedStructures(PymatgenTest):
+class TestGetDisplacedStructures:
     def test_get_displaced_structures(self):
         pmg_s = Structure.from_file(f"{TEST_DIR}/POSCAR-unitcell", primitive=False)
         supercell_matrix = np.diag((2, 1, 2))
@@ -246,7 +246,7 @@ def test_gruneisen_parameter(self):
 
 
 @pytest.mark.skipif(Phonopy is None, reason="Phonopy not present")
-class TestThermalDisplacementMatrices(PymatgenTest):
+class TestThermalDisplacementMatrices:
     def test_get_thermal_displacement_matrix(self):
         list_matrices = get_thermal_displacement_matrices(
             f"{PHONON_DIR}/thermal_displacement_matrices/thermal_displacement_matrices.yaml",
diff --git a/tests/io/test_pwscf.py b/tests/io/test_pwscf.py
index 6e39c8b4019..15743c7a9b6 100644
--- a/tests/io/test_pwscf.py
+++ b/tests/io/test_pwscf.py
@@ -6,12 +6,12 @@
 from pytest import approx
 
 from pymatgen.io.pwscf import PWInput, PWInputError, PWOutput
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/pwscf"
 
 
-class TestPWInput(PymatgenTest):
+class TestPWInput:
     def test_init(self):
         struct = self.get_structure("Li2O")
         with pytest.raises(PWInputError, match="Missing O2- in pseudo specification"):
@@ -542,7 +542,7 @@ def test_custom_decimal_precision_write_and_read_str(self):
         assert pw_str.strip() == str(PWInput.from_str(pw_str)).strip()
 
 
-class TestPWOutput(PymatgenTest):
+class TestPWOutput:
     def setUp(self):
         self.pw_out = PWOutput(f"{TEST_DIR}/Si.pwscf.out")
 
diff --git a/tests/io/test_shengbte.py b/tests/io/test_shengbte.py
index 303c9d094aa..961792df336 100644
--- a/tests/io/test_shengbte.py
+++ b/tests/io/test_shengbte.py
@@ -4,13 +4,13 @@
 from numpy.testing import assert_array_equal
 
 from pymatgen.io.shengbte import Control
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 f90nml = pytest.importorskip("f90nml")
 TEST_DIR = f"{TEST_FILES_DIR}/io/shengbte"
 
 
-class TestShengBTE(PymatgenTest):
+class TestShengBTE:
     def setUp(self):
         self.filename = f"{TEST_DIR}/CONTROL-CSLD_Si"
         self.test_dict = {
diff --git a/tests/io/test_template_input.py b/tests/io/test_template_input.py
index 3be8ae45374..f6ea6e84cf6 100644
--- a/tests/io/test_template_input.py
+++ b/tests/io/test_template_input.py
@@ -5,12 +5,12 @@
 import pytest
 
 from pymatgen.io.template import TemplateInputGen
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io"
 
 
-class TestTemplateInputGen(PymatgenTest):
+class TestTemplateInputGen:
     def test_write_inputs(self):
         input_set = TemplateInputGen().get_input_set(
             template=f"{TEST_DIR}/template_input_file.txt",
diff --git a/tests/io/test_wannier90.py b/tests/io/test_wannier90.py
index 93ac0e256e7..8a43bf62a22 100644
--- a/tests/io/test_wannier90.py
+++ b/tests/io/test_wannier90.py
@@ -8,12 +8,12 @@
 from pytest import approx
 
 from pymatgen.io.wannier90 import Unk
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/io/wannier90"
 
 
-class TestUnk(PymatgenTest):
+class TestUnk:
     def setUp(self):
         rng = np.random.default_rng()
         self.data_std = rng.random((10, 5, 5, 5))
diff --git a/tests/io/test_xcrysden.py b/tests/io/test_xcrysden.py
index 3a13a2cf7b5..095e8f73b6a 100644
--- a/tests/io/test_xcrysden.py
+++ b/tests/io/test_xcrysden.py
@@ -4,10 +4,9 @@
 
 from pymatgen.core.structure import Structure
 from pymatgen.io.xcrysden import XSF
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestXSF(PymatgenTest):
+class TestXSF:
     def setUp(self):
         self.coords = [[0, 0, 0], [0.75, 0.5, 0.75]]
         self.lattice = [
diff --git a/tests/io/vasp/test_inputs.py b/tests/io/vasp/test_inputs.py
index 1616ff4e5e7..13e28f4a4eb 100644
--- a/tests/io/vasp/test_inputs.py
+++ b/tests/io/vasp/test_inputs.py
@@ -38,7 +38,7 @@
     VaspInput,
     _gen_potcar_summary_stats,
 )
-from pymatgen.util.testing import FAKE_POTCAR_DIR, TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR, PymatgenTest
+from pymatgen.util.testing import FAKE_POTCAR_DIR, TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR
 
 # Filter some expected warnings
 warnings.filterwarnings(
@@ -72,7 +72,7 @@ def _mock_complete_potcar_summary_stats(monkeypatch: pytest.MonkeyPatch) -> None
 @pytest.mark.filterwarnings(
     "ignore:POTCAR data with symbol .* is not known to pymatgen:pymatgen.io.vasp.inputs.UnknownPotcarWarning"
 )
-class TestPoscar(PymatgenTest):
+class TestPoscar:
     def test_init(self):
         comp = Structure.from_file(f"{VASP_IN_DIR}/POSCAR").composition
         assert comp == Composition("Fe4P4O16")
@@ -649,7 +649,7 @@ def test_vasp_6_4_2_format(self):
         assert poscar.structure.formula == "Li4 Fe4 P4 O16"
 
 
-class TestIncar(PymatgenTest):
+class TestIncar:
     def setUp(self):
         self.incar = Incar.from_file(f"{VASP_IN_DIR}/INCAR")
 
@@ -1537,7 +1537,7 @@ def test_copy(self):
 @pytest.mark.filterwarnings(
     "ignore:POTCAR data with symbol .* is not known to pymatgen:pymatgen.io.vasp.inputs.UnknownPotcarWarning"
 )
-class TestPotcar(PymatgenTest):
+class TestPotcar:
     def setUp(self):
         SETTINGS.setdefault("PMG_VASP_PSP_DIR", str(TEST_FILES_DIR))
         self.filepath = f"{FAKE_POTCAR_DIR}/POTCAR.gz"
@@ -1616,7 +1616,7 @@ def test_pickle(self):
 @pytest.mark.filterwarnings(
     "ignore:POTCAR data with symbol .* is not known to pymatgen:pymatgen.io.vasp.inputs.UnknownPotcarWarning"
 )
-class TestVaspInput(PymatgenTest):
+class TestVaspInput:
     def setUp(self):
         filepath = f"{VASP_IN_DIR}/INCAR"
         incar = Incar.from_file(filepath)
diff --git a/tests/io/vasp/test_optics.py b/tests/io/vasp/test_optics.py
index 3a2caf7a94a..a898c5fb7eb 100644
--- a/tests/io/vasp/test_optics.py
+++ b/tests/io/vasp/test_optics.py
@@ -7,7 +7,7 @@
 
 from pymatgen.io.vasp.optics import DielectricFunctionCalculator, delta_func, delta_methfessel_paxton, step_func
 from pymatgen.io.vasp.outputs import Vasprun
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Jimmy-Xuan Shen"
 __copyright__ = "Copyright 2022, The Materials Project"
@@ -16,7 +16,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/io/vasp"
 
 
-class TestVasprun(PymatgenTest):
+class TestVasprun:
     def test_optics(self):
         eps_data_path = f"{TEST_DIR}/fixtures/reproduce_eps"
         vrun = Vasprun(f"{eps_data_path}/vasprun.xml")
diff --git a/tests/io/vasp/test_outputs.py b/tests/io/vasp/test_outputs.py
index e02b9ac027a..e67c241bf8a 100644
--- a/tests/io/vasp/test_outputs.py
+++ b/tests/io/vasp/test_outputs.py
@@ -41,7 +41,7 @@
     Xdatcar,
 )
 from pymatgen.io.wannier90 import Unk
-from pymatgen.util.testing import FAKE_POTCAR_DIR, TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR, PymatgenTest
+from pymatgen.util.testing import FAKE_POTCAR_DIR, TEST_FILES_DIR, VASP_IN_DIR, VASP_OUT_DIR
 
 try:
     import h5py
@@ -53,7 +53,7 @@
 kpts_opt_vrun_path = f"{TEST_DIR}/fixtures/kpoints_opt/vasprun.xml.gz"
 
 
-class TestVasprun(PymatgenTest):
+class TestVasprun:
     def test_vasprun_ml(self):
         # Test for ML MD simulation
         # The trajectory data is stored in md_data
@@ -832,7 +832,7 @@ def test_parse_potcar_cwd_relative(self):
                 assert vrun.potcar_spec[ipot]["summary_stats"] == potcar[ipot]._summary_stats
 
 
-class TestOutcar(PymatgenTest):
+class TestOutcar:
     def test_init(self):
         outcar = Outcar(f"{VASP_OUT_DIR}/OUTCAR.gz")
         expected_mag = (
@@ -1423,7 +1423,7 @@ def test_read_table_pattern(self):
             )
 
 
-class TestBSVasprun(PymatgenTest):
+class TestBSVasprun:
     def test_get_band_structure(self):
         filepath = f"{VASP_OUT_DIR}/vasprun_Si_bands.xml.gz"
         vasprun = BSVasprun(filepath, parse_potcar_file=False)
@@ -1477,7 +1477,7 @@ def test_kpoints_opt(self):
         assert {*vrun_dct["output"]} >= {"eigenvalues", "eigenvalues_kpoints_opt"}
 
 
-class TestOszicar(PymatgenTest):
+class TestOszicar:
     def test_init(self):
         fpath = f"{VASP_OUT_DIR}/OSZICAR"
         oszicar = Oszicar(fpath)
@@ -1493,7 +1493,7 @@ def test_static(self):
         assert set(oszicar.ionic_steps[-1]) == set({"F", "E0", "dE", "mag"})
 
 
-class TestLocpot(PymatgenTest):
+class TestLocpot:
     def test_init(self):
         filepath = f"{VASP_OUT_DIR}/LOCPOT.gz"
         locpot = Locpot.from_file(filepath)
@@ -1514,7 +1514,7 @@ def test_vasp_6x_style(self):
         assert {str(ele) for ele in locpot.structure.composition} == {"Mg", "Si"}
 
 
-class TestChgcar(PymatgenTest):
+class TestChgcar:
     @classmethod
     def setUpClass(cls):
         filepath = f"{VASP_OUT_DIR}/CHGCAR.nospin.gz"
@@ -1638,7 +1638,7 @@ def test_as_dict_and_from_dict(self):
         )
 
 
-class TestAeccars(PymatgenTest):
+class TestAeccars:
     # https://github.com/materialsproject/pymatgen/pull/3343
     def test_read_write_file(self):
         aeccar0_test = Chgcar.from_file(f"{TEST_FILES_DIR}/command_line/bader/AECCAR0.gz")
@@ -1654,7 +1654,7 @@ def test_read_write_file(self):
         assert_allclose(aeccar2.data["total"], aeccar2_read.data["total"])
 
 
-class TestElfcar(PymatgenTest):
+class TestElfcar:
     def test_init(self):
         elfcar = Elfcar.from_file(f"{VASP_OUT_DIR}/ELFCAR.gz")
         assert approx(np.mean(elfcar.data["total"])) == 0.19076207645194002
@@ -1674,7 +1674,7 @@ def test_interpolation(self):
         assert len(elfcar.linear_slice([0.0, 0.0, 0.0], [1.0, 1.0, 1.0])) == 100
 
 
-class TestProcar(PymatgenTest):
+class TestProcar:
     def test_init(self):
         filepath = f"{VASP_OUT_DIR}/PROCAR.simple"
         procar = Procar(filepath)
@@ -1817,7 +1817,7 @@ def test_init(self):
         # TODO: test get_phonon_frequencies once cross-checked
 
 
-class TestWavecar(PymatgenTest):
+class TestWavecar:
     def setUp(self):
         latt_mat = np.array(np.eye(3) * 10, dtype=float)  # lattice vectors
         self.vol = np.dot(latt_mat[0, :], np.cross(latt_mat[1, :], latt_mat[2, :]))  # unit cell volume
@@ -2095,7 +2095,7 @@ def test_write_unks(self):
         assert unk == unk_ncl
 
 
-class TestEigenval(PymatgenTest):
+class TestEigenval:
     def test_init(self):
         eig = Eigenval(f"{VASP_OUT_DIR}/EIGENVAL.gz")
         assert eig.ispin == 1
@@ -2135,7 +2135,7 @@ def test_eigenvalue_band_properties_separate_spins(self):
         assert props[3][1]
 
 
-class TestWaveder(PymatgenTest):
+class TestWaveder:
     def setUp(self):
         wder = Waveder.from_binary(f"{VASP_OUT_DIR}/WAVEDER", "float64")
         assert wder.nbands == 36
@@ -2168,7 +2168,7 @@ def _check(wder):
         _check(wderf)
 
 
-class TestWSWQ(PymatgenTest):
+class TestWSWQ:
     def setUp(self):
         self.wswq = WSWQ.from_file(f"{VASP_OUT_DIR}/WSWQ.gz")
 
diff --git a/tests/io/vasp/test_sets.py b/tests/io/vasp/test_sets.py
index 6b4f9ceebdb..6dd438c052b 100644
--- a/tests/io/vasp/test_sets.py
+++ b/tests/io/vasp/test_sets.py
@@ -91,7 +91,7 @@ def test_yb_2_warning(input_set: VaspInputSet) -> None:
     assert expected in str(record[0].message)
 
 
-class TestSetChangeCheck(PymatgenTest):
+class TestSetChangeCheck:
     def test_sets_changed(self):
         msg = (
             "WARNING! These tests will fail when you change an input set. They are included "
@@ -128,7 +128,7 @@ def test_sets_changed(self):
             assert hash_str == known_hashes[input_set], f"{input_set=}\n{msg}"
 
 
-class TestVaspInputSet(PymatgenTest):
+class TestVaspInputSet:
     @classmethod
     def setUpClass(cls):
         filepath = f"{VASP_IN_DIR}/POSCAR"
@@ -165,7 +165,7 @@ def test_as_dict(self):
         assert dict_set.potcar_functional == dict_set.user_potcar_functional
 
 
-class TestMITMPRelaxSet(PymatgenTest):
+class TestMITMPRelaxSet:
     @classmethod
     def setUpClass(cls):
         cls.set = MITRelaxSet
@@ -718,7 +718,7 @@ def test_get_nedos(self):
         assert vis._get_nedos(0.1) == pytest.approx(741, abs=1)
 
 
-class TestMPStaticSet(PymatgenTest):
+class TestMPStaticSet:
     def setUp(self):
         self.set = MPStaticSet
 
@@ -870,7 +870,7 @@ def test_grid_size_from_struct(self):
         )
 
 
-class TestMatPESStaticSet(PymatgenTest):
+class TestMatPESStaticSet:
     def setUp(self):
         self.struct = Structure.from_file(f"{VASP_IN_DIR}/POSCAR")
         self.prev_incar = Incar.from_file(f"{VASP_IN_DIR}/INCAR")
@@ -987,7 +987,7 @@ def test_from_prev_calc(self):
         assert vis.kpoints is None
 
 
-class TestMPNonSCFSet(PymatgenTest):
+class TestMPNonSCFSet:
     def setUp(self):
         self.set = MPNonSCFSet
 
@@ -1153,7 +1153,7 @@ def test_user_kpoint_override(self):
         assert vis.kpoints.style == Kpoints.supported_modes.Gamma
 
 
-class TestMagmomLdau(PymatgenTest):
+class TestMagmomLdau:
     def test_structure_from_prev_run(self):
         vrun = Vasprun(f"{VASP_OUT_DIR}/vasprun.magmom_ldau.xml.gz")
         structure = vrun.final_structure
@@ -1188,7 +1188,7 @@ def test_ln_magmom(self):
             assert vis.incar["MAGMOM"] == magmom_ans
 
 
-class TestMITMDSet(PymatgenTest):
+class TestMITMDSet:
     def setUp(self):
         self.set = MITMDSet
         filepath = f"{VASP_IN_DIR}/POSCAR"
@@ -1230,7 +1230,7 @@ def test_user_heat_speed(self):
 
 
 @skip_if_no_psp_dir
-class TestMVLNPTMDSet(PymatgenTest):
+class TestMVLNPTMDSet:
     def setUp(self):
         file_path = f"{VASP_IN_DIR}/POSCAR"
         self.struct = Structure.from_file(file_path)
@@ -1266,7 +1266,7 @@ def test_as_from_dict(self):
         assert input_set.incar["NSW"] == 1000
 
 
-class TestMPMDSet(PymatgenTest):
+class TestMPMDSet:
     def setUp(self):
         filepath = f"{VASP_IN_DIR}/POSCAR"
         self.struct = Structure.from_file(filepath)
@@ -1308,7 +1308,7 @@ def test_as_from_dict(self):
         assert v.incar["NSW"] == 1000
 
 
-class TestMITNEBSet(PymatgenTest):
+class TestMITNEBSet:
     def setUp(self):
         c1 = [[0.5] * 3, [0.9] * 3]
         c2 = [[0.5] * 3, [0.9, 0.1, 0.1]]
@@ -1356,7 +1356,7 @@ def test_write_input(self):
         assert not os.path.isfile("04/POSCAR")
 
 
-class TestMPSOCSet(PymatgenTest):
+class TestMPSOCSet:
     def setUp(self):
         self.set = MPSOCSet
 
@@ -1393,7 +1393,7 @@ def test_override_from_prev_calc(self):
         assert vis.incar["SIGMA"] == 0.025
 
 
-class TestMPNMRSet(PymatgenTest):
+class TestMPNMRSet:
     def test_incar(self):
         filepath = f"{TEST_FILES_DIR}/cif/Li.cif"
         structure = Structure.from_file(filepath)
@@ -1415,7 +1415,7 @@ def test_incar(self):
 
 
 @skip_if_no_psp_dir
-class TestMVLSlabSet(PymatgenTest):
+class TestMVLSlabSet:
     def setUp(self):
         self.set = MVLSlabSet
         struct = self.get_structure("Li2O")
@@ -1487,7 +1487,7 @@ def test_as_from_dict(self):
         assert "structure" not in self.vis.as_dict(verbosity=1)
 
 
-class TestMVLElasticSet(PymatgenTest):
+class TestMVLElasticSet:
     def test_incar(self):
         mvlparam = MVLElasticSet(self.get_structure("Graphite"))
         incar = mvlparam.incar
@@ -1498,7 +1498,7 @@ def test_incar(self):
 
 
 @skip_if_no_psp_dir
-class TestMVLGWSet(PymatgenTest):
+class TestMVLGWSet:
     def setUp(self):
         self.set = MVLGWSet
         self.struct = PymatgenTest.get_structure("Li2O")
@@ -1576,7 +1576,7 @@ def test_bse(self):
         assert mvlgwgbse1.incar["ALGO"] == "Bse"
 
 
-class TestMPHSERelaxSet(PymatgenTest):
+class TestMPHSERelaxSet:
     def setUp(self):
         self.structure = dummy_structure
         self.set = MPHSERelaxSet
@@ -1643,7 +1643,7 @@ def test_override_from_prev_calc(self):
         assert "VDW_S8" in vis_bj.incar
 
 
-class TestMPHSEBS(PymatgenTest):
+class TestMPHSEBS:
     def setUp(self):
         self.set = MPHSEBSSet
 
@@ -1699,7 +1699,7 @@ def test_override_from_prev_calc(self):
         assert len(vis.kpoints.kpts) == 180
 
 
-class TestMVLScanRelaxSet(PymatgenTest):
+class TestMVLScanRelaxSet:
     def setUp(self):
         self.set = MVLScanRelaxSet
         file_path = f"{VASP_IN_DIR}/POSCAR"
@@ -1777,7 +1777,7 @@ def test_as_from_dict(self):
         assert v.user_incar_settings["NSW"] == 500
 
 
-class TestMPScanRelaxSet(PymatgenTest):
+class TestMPScanRelaxSet:
     def setUp(self):
         file_path = f"{VASP_IN_DIR}/POSCAR"
         self.struct = Structure.from_file(file_path)
@@ -1898,7 +1898,7 @@ def test_write_input(self):
         assert os.path.isfile(f"{self.tmp_path}/POSCAR")
 
 
-class TestMPScanStaticSet(PymatgenTest):
+class TestMPScanStaticSet:
     def setUp(self):
         self.set = MPScanStaticSet
         self.prev_run = f"{TEST_DIR}/fixtures/scan_relaxation"
@@ -1988,7 +1988,7 @@ def test_override_from_prev_calc(self):
         assert lepsilon_vis.incar.get("NPAR") is None
 
 
-class TestFunc(PymatgenTest):
+class TestFunc:
     @skip_if_no_psp_dir
     def test_batch_write_input(self):
         structs = list(map(PymatgenTest.get_structure, ("Li2O", "LiFePO4")))
@@ -2000,7 +2000,7 @@ def test_batch_write_input(self):
 
 
 @skip_if_no_psp_dir
-class TestMVLGBSet(PymatgenTest):
+class TestMVLGBSet:
     def setUp(self):
         filepath = f"{TEST_FILES_DIR}/cif/Li.cif"
         self.struct = Structure.from_file(filepath)
@@ -2026,7 +2026,7 @@ def test_kpoints(self):
         assert kpoints.kpts == [(k_a, k_b, 1)]
 
 
-class TestMVLRelax52Set(PymatgenTest):
+class TestMVLRelax52Set:
     def setUp(self):
         self.set = MVLRelax52Set
         file_path = f"{VASP_IN_DIR}/POSCAR"
@@ -2064,7 +2064,7 @@ def test_as_from_dict(self):
         assert vasp_input.incar["NSW"] == 500
 
 
-class TestLobsterSet(PymatgenTest):
+class TestLobsterSet:
     def setUp(self):
         self.set = LobsterSet
         file_path = f"{VASP_IN_DIR}/POSCAR"
@@ -2163,7 +2163,7 @@ def test_as_from_dict(self):
 
 
 @skip_if_no_psp_dir
-class TestMPAbsorptionSet(PymatgenTest):
+class TestMPAbsorptionSet:
     def setUp(self):
         file_path = f"{TEST_DIR}/fixtures/absorption/static/POSCAR"
         self.structure = Structure.from_file(file_path)
diff --git a/tests/io/xtb/test_inputs.py b/tests/io/xtb/test_inputs.py
index 546386c6391..16d5be8e0fe 100644
--- a/tests/io/xtb/test_inputs.py
+++ b/tests/io/xtb/test_inputs.py
@@ -2,7 +2,7 @@
 
 from pymatgen.core.structure import Molecule
 from pymatgen.io.xtb.inputs import CRESTInput
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Alex Epstein"
 __copyright__ = "Copyright 2020, The Materials Project"
@@ -12,7 +12,7 @@
 EXPECTED_DIR = f"{TEST_FILES_DIR}/io/xtb/expected_output"
 
 
-class TestCRESTInput(PymatgenTest):
+class TestCRESTInput:
     """
     Checks that all attributes of CRESTInput match the expected values for
     sample inputs.
diff --git a/tests/io/xtb/test_outputs.py b/tests/io/xtb/test_outputs.py
index c4d3fe69777..e617996b8f1 100644
--- a/tests/io/xtb/test_outputs.py
+++ b/tests/io/xtb/test_outputs.py
@@ -7,7 +7,7 @@
 from pymatgen.core.structure import Molecule
 from pymatgen.io.qchem.outputs import check_for_structure_changes
 from pymatgen.io.xtb.outputs import CRESTOutput
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 try:
     from openbabel import openbabel
@@ -23,7 +23,7 @@
 EXPECTED_DIR = f"{TEST_FILES_DIR}/io/xtb/expected_output"
 
 
-class TestCRESTOutput(PymatgenTest):
+class TestCRESTOutput:
     """
     Checks that all attributes of CRESTOutput match the expected values for a
     sample CREST output directory.
diff --git a/tests/optimization/test_neighbors.py b/tests/optimization/test_neighbors.py
index 3542acd20ff..5ddd14f638e 100644
--- a/tests/optimization/test_neighbors.py
+++ b/tests/optimization/test_neighbors.py
@@ -4,10 +4,9 @@
 
 from pymatgen.core.lattice import Lattice
 from pymatgen.optimization.neighbors import find_points_in_spheres
-from pymatgen.util.testing import PymatgenTest
 
 
-class TestNeighbors(PymatgenTest):
+class TestNeighbors:
     def setUp(self):
         self.lattice = Lattice.cubic(10.0)
         self.cubic = self.lattice
diff --git a/tests/phonon/test_bandstructure.py b/tests/phonon/test_bandstructure.py
index 7f449792544..6545edb1e27 100644
--- a/tests/phonon/test_bandstructure.py
+++ b/tests/phonon/test_bandstructure.py
@@ -8,12 +8,12 @@
 
 from pymatgen.electronic_structure.bandstructure import Kpoint
 from pymatgen.phonon.bandstructure import PhononBandStructureSymmLine
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/electronic_structure/bandstructure"
 
 
-class TestPhononBandStructureSymmLine(PymatgenTest):
+class TestPhononBandStructureSymmLine:
     def setUp(self):
         with open(f"{TEST_DIR}/NaCl_phonon_bandstructure.json") as file:
             dct = json.load(file)
diff --git a/tests/phonon/test_dos.py b/tests/phonon/test_dos.py
index e586604d81e..a301540e4f0 100644
--- a/tests/phonon/test_dos.py
+++ b/tests/phonon/test_dos.py
@@ -9,12 +9,12 @@
 
 from pymatgen.core import Element
 from pymatgen.phonon.dos import CompletePhononDos, PhononDos
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/phonon/dos"
 
 
-class TestPhononDos(PymatgenTest):
+class TestPhononDos:
     def setUp(self):
         with open(f"{TEST_DIR}/NaCl_ph_dos.json") as file:
             self.dos = PhononDos.from_dict(json.load(file))
@@ -182,7 +182,7 @@ def test_dos_fp_exceptions(self):
             self.dos.get_dos_fp_similarity(dos_fp, dos_fp2, col=1, metric=metric, normalize=False)
 
 
-class TestCompletePhononDos(PymatgenTest):
+class TestCompletePhononDos:
     def setUp(self):
         with open(f"{TEST_DIR}/NaCl_complete_ph_dos.json") as file:
             self.cdos = CompletePhononDos.from_dict(json.load(file))
diff --git a/tests/phonon/test_gruneisen.py b/tests/phonon/test_gruneisen.py
index 748fd68c8c2..164790bfc91 100644
--- a/tests/phonon/test_gruneisen.py
+++ b/tests/phonon/test_gruneisen.py
@@ -9,7 +9,7 @@
 from pymatgen.io.phonopy import get_gruneisen_ph_bs_symm_line, get_gruneisenparameter
 from pymatgen.phonon.gruneisen import GruneisenParameter
 from pymatgen.phonon.plotter import GruneisenPhononBandStructureSymmLine, GruneisenPhononBSPlotter, GruneisenPlotter
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 try:
     import phonopy
@@ -21,7 +21,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/phonon/gruneisen"
 
 
-class TestGruneisenPhononBandStructureSymmLine(PymatgenTest):
+class TestGruneisenPhononBandStructureSymmLine:
     def setUp(self) -> None:
         self.bs_symm_line = get_gruneisen_ph_bs_symm_line(
             gruneisen_path=f"{TEST_DIR}/gruneisen_eq_plus_minus_InP.yaml",
@@ -76,7 +76,7 @@ def test_as_dict_from_dict(self):
 
 
 @pytest.mark.skipif(TotalDos is None, reason="Phonopy not present")
-class TestGruneisenParameter(PymatgenTest):
+class TestGruneisenParameter:
     def setUp(self) -> None:
         self.gruneisen_obj = get_gruneisenparameter(
             f"{TEST_DIR}/gruneisen_mesh_InP.yaml",
diff --git a/tests/phonon/test_ir_spectra.py b/tests/phonon/test_ir_spectra.py
index 7a7eb40f4ce..491bbc24e7d 100644
--- a/tests/phonon/test_ir_spectra.py
+++ b/tests/phonon/test_ir_spectra.py
@@ -2,10 +2,10 @@
 
 from monty.serialization import loadfn
 
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 
-class TestIRDielectricTensor(PymatgenTest):
+class TestIRDielectricTensor:
     def setUp(self):
         self.ir_spectra = loadfn(f"{TEST_FILES_DIR}/phonon/dos/ir_spectra_mp-991652_DDB.json")
 
diff --git a/tests/phonon/test_thermal_displacements.py b/tests/phonon/test_thermal_displacements.py
index aeb26a4dffc..7f138a9012a 100644
--- a/tests/phonon/test_thermal_displacements.py
+++ b/tests/phonon/test_thermal_displacements.py
@@ -6,12 +6,12 @@
 
 from pymatgen.core.structure import Structure
 from pymatgen.phonon.thermal_displacements import ThermalDisplacementMatrices
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/phonon/thermal_displacement_matrices"
 
 
-class TestThermalDisplacement(PymatgenTest):
+class TestThermalDisplacement:
     """Test data from J. George's matlab code https://github.com/JaGeo/MolecularToolbox."""
 
     def setUp(self) -> None:
diff --git a/tests/symmetry/test_analyzer.py b/tests/symmetry/test_analyzer.py
index 7966c815ce9..759e6e64a27 100644
--- a/tests/symmetry/test_analyzer.py
+++ b/tests/symmetry/test_analyzer.py
@@ -24,7 +24,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/symmetry/analyzer"
 
 
-class TestSpacegroupAnalyzer(PymatgenTest):
+class TestSpacegroupAnalyzer:
     def setUp(self):
         self.structure = Structure.from_file(f"{VASP_IN_DIR}/POSCAR")
         self.sg = SpacegroupAnalyzer(self.structure, 0.001)
@@ -537,7 +537,7 @@ def test_are_symmetrically_equivalent(self):
 )
 
 
-class TestPointGroupAnalyzer(PymatgenTest):
+class TestPointGroupAnalyzer:
     def test_spherical(self):
         pg_analyzer = PointGroupAnalyzer(CH4)
         assert pg_analyzer.sch_symbol == "Td"
diff --git a/tests/symmetry/test_kpath_hin.py b/tests/symmetry/test_kpath_hin.py
index 2a7cce41712..1cadbc40f7e 100644
--- a/tests/symmetry/test_kpath_hin.py
+++ b/tests/symmetry/test_kpath_hin.py
@@ -6,12 +6,11 @@
 from pymatgen.core.lattice import Lattice
 from pymatgen.core.structure import Structure
 from pymatgen.symmetry.kpath import KPathSeek
-from pymatgen.util.testing import PymatgenTest
 
 pytest.importorskip("seekpath", reason="seekpath not installed")
 
 
-class TestKPathSeek(PymatgenTest):
+class TestKPathSeek:
     def test_kpath_generation(self):
         triclinic = [1, 2]
         monoclinic = range(3, 16)
diff --git a/tests/symmetry/test_kpath_lm.py b/tests/symmetry/test_kpath_lm.py
index 479ffecb65d..b203ddcae72 100644
--- a/tests/symmetry/test_kpath_lm.py
+++ b/tests/symmetry/test_kpath_lm.py
@@ -8,10 +8,10 @@
 from pymatgen.core.structure import Structure
 from pymatgen.symmetry.analyzer import SpacegroupAnalyzer
 from pymatgen.symmetry.kpath import KPathLatimerMunro
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 
-class TestKPathLatimerMunro(PymatgenTest):
+class TestKPathLatimerMunro:
     def test_kpath_generation(self):
         triclinic = [1, 2]
         monoclinic = range(3, 16)
diff --git a/tests/symmetry/test_kpath_sc.py b/tests/symmetry/test_kpath_sc.py
index d88c97f79dd..72b1b4eb716 100644
--- a/tests/symmetry/test_kpath_sc.py
+++ b/tests/symmetry/test_kpath_sc.py
@@ -6,12 +6,12 @@
 from pymatgen.core.lattice import Lattice
 from pymatgen.core.structure import Structure
 from pymatgen.symmetry.kpath import KPathSetyawanCurtarolo
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 TEST_DIR = f"{TEST_FILES_DIR}/symmetry/space_group_structs"
 
 
-class TestBandStructureSC(PymatgenTest):
+class TestBandStructureSC:
     def test_kpath_generation(self):
         triclinic = [1, 2]
         monoclinic = range(3, 16)
diff --git a/tests/symmetry/test_kpaths.py b/tests/symmetry/test_kpaths.py
index 87c8bd16480..46a0f51671b 100644
--- a/tests/symmetry/test_kpaths.py
+++ b/tests/symmetry/test_kpaths.py
@@ -7,7 +7,7 @@
 from pymatgen.core.lattice import Lattice
 from pymatgen.core.structure import Structure
 from pymatgen.symmetry.bandstructure import HighSymmKpath
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 try:
     from seekpath import get_path
@@ -17,7 +17,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/electronic_structure/bandstructure"
 
 
-class TestHighSymmKpath(PymatgenTest):
+class TestHighSymmKpath:
     @pytest.mark.skipif(get_path is None, reason="No seek path present.")
     def test_kpath_generation(self):
         triclinic = [1, 2]
diff --git a/tests/symmetry/test_maggroups.py b/tests/symmetry/test_maggroups.py
index 72f184d553f..3e664592d3b 100644
--- a/tests/symmetry/test_maggroups.py
+++ b/tests/symmetry/test_maggroups.py
@@ -6,7 +6,6 @@
 from pymatgen.core.lattice import Lattice
 from pymatgen.symmetry.groups import SpaceGroup
 from pymatgen.symmetry.maggroups import MagneticSpaceGroup
-from pymatgen.util.testing import PymatgenTest
 
 __author__ = "Matthew Horton"
 __copyright__ = "Copyright 2017, The Materials Project"
@@ -17,7 +16,7 @@
 __date__ = "Feb 2017"
 
 
-class TestMagneticSpaceGroup(PymatgenTest):
+class TestMagneticSpaceGroup:
     def setUp(self):
         self.msg_1 = MagneticSpaceGroup([70, 530])
         self.msg_2 = MagneticSpaceGroup([62, 448])
diff --git a/tests/symmetry/test_site_symmetries.py b/tests/symmetry/test_site_symmetries.py
index 1b33f3a11f0..3bdd7c5f7f9 100644
--- a/tests/symmetry/test_site_symmetries.py
+++ b/tests/symmetry/test_site_symmetries.py
@@ -6,7 +6,7 @@
 from monty.json import MontyDecoder
 
 from pymatgen.symmetry import site_symmetries as ss
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 
 __author__ = "Handong Ling"
 __version__ = "0.1"
@@ -18,7 +18,7 @@
 TEST_DIR = f"{TEST_FILES_DIR}/symmetry/site_symmetries"
 
 
-class TestSiteSymmetries(PymatgenTest):
+class TestSiteSymmetries:
     def setUp(self):
         with gzip.open(f"{TEST_DIR}/point_ops.json.gz", mode="rt") as file:
             self.point_ops = MontyDecoder().process_decoded(json.load(file))
diff --git a/tests/transformations/test_advanced_transformations.py b/tests/transformations/test_advanced_transformations.py
index 2f73ace7cd3..479fbde5302 100644
--- a/tests/transformations/test_advanced_transformations.py
+++ b/tests/transformations/test_advanced_transformations.py
@@ -276,7 +276,7 @@ def test_as_dict(self):
 
 
 @pytest.mark.skipif(not enumlib_present, reason="enum_lib not present.")
-class TestMagOrderingTransformation(PymatgenTest):
+class TestMagOrderingTransformation:
     def setUp(self):
         lattice = Lattice.cubic(4.17)
         species = ["Ni", "O"]
@@ -488,7 +488,7 @@ def test_advanced_usage(self):
 
 
 @pytest.mark.skipif(not enumlib_present, reason="enum_lib not present.")
-class TestDopingTransformation(PymatgenTest):
+class TestDopingTransformation:
     def test_apply_transformation(self):
         structure = PymatgenTest.get_structure("LiFePO4")
         spga = SpacegroupAnalyzer(structure, 0.1)
@@ -551,7 +551,7 @@ def test_find_codopant(self):
         assert find_codopant(Species("Fe", 2), 3) == Species("In", 3)
 
 
-class TestSlabTransformation(PymatgenTest):
+class TestSlabTransformation:
     def test_apply_transformation(self):
         struct = self.get_structure("LiFePO4")
         trans = SlabTransformation([0, 0, 1], 10, 10, shift=0.25)
@@ -570,7 +570,7 @@ def test_apply_transformation(self):
         assert_allclose(slab_from_gen.cart_coords, slab_from_trans.cart_coords)
 
 
-class TestGrainBoundaryTransformation(PymatgenTest):
+class TestGrainBoundaryTransformation:
     def test_apply_transformation(self):
         Al_bulk = Structure.from_spacegroup("Fm-3m", Lattice.cubic(2.8575585), ["Al"], [[0, 0, 0]])
         gb_gen_params_s5 = {
@@ -590,7 +590,7 @@ def test_apply_transformation(self):
         assert_allclose(gb_from_generator.cart_coords, gb_from_trans.cart_coords)
 
 
-class TestDisorderedOrderedTransformation(PymatgenTest):
+class TestDisorderedOrderedTransformation:
     def test_apply_transformation(self):
         # nonsensical example just for testing purposes
         struct = self.get_structure("BaNiO3")
@@ -603,7 +603,7 @@ def test_apply_transformation(self):
 
 
 @pytest.mark.skipif(not mcsqs_cmd, reason="mcsqs not present.")
-class TestSQSTransformation(PymatgenTest):
+class TestSQSTransformation:
     def test_apply_transformation(self):
         pzt_structs = loadfn(f"{TEST_FILES_DIR}/io/atat/mcsqs/pzt-structs.json")
         trans = SQSTransformation(scaling=[2, 1, 1], search_time=0.01, instances=1, wd=0)
@@ -649,7 +649,7 @@ def test_spin(self):
 
 
 @pytest.mark.skipif(ClusterSpace is None, reason="icet not installed.")
-class TestSQSTransformationIcet(PymatgenTest):
+class TestSQSTransformationIcet:
     stored_run: dict = loadfn(f"{TEST_FILES_DIR}/transformations/icet-sqs-fcc-Mg_75-Al_25-scaling_8.json.gz")
     scaling: int = 8
 
@@ -699,7 +699,7 @@ def test_monte_carlo(self):
             assert isinstance(sqs_output[0][key], val)
 
 
-class TestCubicSupercellTransformation(PymatgenTest):
+class TestCubicSupercellTransformation:
     def test_apply_transformation_cubic_supercell(self):
         structure = self.get_structure("TlBiSe2")
         min_atoms = 100
@@ -848,7 +848,7 @@ def test_apply_transformation_orthorhombic_supercell(self):
         assert transformed_cubic.lattice.angles == transformed_orthorhombic.lattice.angles
 
 
-class TestAddAdsorbateTransformation(PymatgenTest):
+class TestAddAdsorbateTransformation:
     def test_apply_transformation(self):
         co = Molecule(["C", "O"], [[0, 0, 0], [0, 0, 1.23]])
         trans = AddAdsorbateTransformation(co)
@@ -859,7 +859,7 @@ def test_apply_transformation(self):
         assert out.reduced_formula == "Pt4CO"
 
 
-class TestSubstituteSurfaceSiteTransformation(PymatgenTest):
+class TestSubstituteSurfaceSiteTransformation:
     def test_apply_transformation(self):
         trans = SubstituteSurfaceSiteTransformation("Au")
         pt = Structure(Lattice.cubic(5), ["Pt"], [[0, 0, 0]])  # fictitious
@@ -870,7 +870,7 @@ def test_apply_transformation(self):
 
 
 @pytest.mark.skipif(not hiphive, reason="hiphive not present")
-class TestMonteCarloRattleTransformation(PymatgenTest):
+class TestMonteCarloRattleTransformation:
     def test_apply_transformation(self):
         struct = self.get_structure("Si")
         mcrt = MonteCarloRattleTransformation(0.01, 2, seed=1)
diff --git a/tests/transformations/test_site_transformations.py b/tests/transformations/test_site_transformations.py
index 0e97aceabc0..fc778b97257 100644
--- a/tests/transformations/test_site_transformations.py
+++ b/tests/transformations/test_site_transformations.py
@@ -17,14 +17,13 @@
     ReplaceSiteSpeciesTransformation,
     TranslateSitesTransformation,
 )
-from pymatgen.util.testing import PymatgenTest
 
 enum_cmd = which("enum.x") or which("multienum.x")
 makestr_cmd = which("makestr.x") or which("makeStr.x") or which("makeStr.py")
 enumlib_present = enum_cmd and makestr_cmd
 
 
-class TestTranslateSitesTransformation(PymatgenTest):
+class TestTranslateSitesTransformation:
     def setUp(self):
         coords = [
             [0, 0, 0],
@@ -264,7 +263,7 @@ def test_str(self):
         )
 
 
-class TestAddSitePropertyTransformation(PymatgenTest):
+class TestAddSitePropertyTransformation:
     def test_apply_transformation(self):
         struct = self.get_structure("Li2O2")
         sd = [[True, True, True] for _ in struct]
@@ -279,7 +278,7 @@ def test_apply_transformation(self):
             assert_allclose(trans_set.site_properties[prop], manually_set.site_properties[prop])
 
 
-class TestRadialSiteDistortionTransformation(PymatgenTest):
+class TestRadialSiteDistortionTransformation:
     def setUp(self):
         self.molecule = Molecule(
             species=["C", "H", "H", "H", "H", "H", "H", "H", "H", "H", "H", "H", "H"],
diff --git a/tests/util/test_io.py b/tests/util/test_io.py
index 09458240656..1c810ab98a3 100644
--- a/tests/util/test_io.py
+++ b/tests/util/test_io.py
@@ -1,10 +1,10 @@
 from __future__ import annotations
 
 from pymatgen.util.io_utils import micro_pyawk
-from pymatgen.util.testing import VASP_OUT_DIR, PymatgenTest
+from pymatgen.util.testing import VASP_OUT_DIR
 
 
-class TestFunc(PymatgenTest):
+class TestFunc:
     def test_micro_pyawk(self):
         data = []
 
diff --git a/tests/util/test_plotting.py b/tests/util/test_plotting.py
index ec68c960d88..e9771589e06 100644
--- a/tests/util/test_plotting.py
+++ b/tests/util/test_plotting.py
@@ -3,7 +3,6 @@
 import matplotlib.pyplot as plt
 
 from pymatgen.util.plotting import periodic_table_heatmap, van_arkel_triangle
-from pymatgen.util.testing import PymatgenTest
 
 try:
     import pymatviz
@@ -12,7 +11,7 @@
     pymatviz = None
 
 
-class TestFunc(PymatgenTest):
+class TestFunc:
     def test_plot_periodic_heatmap(self):
         random_data = {"Te": 0.11083, "Au": 0.75756, "Th": 1.24758, "Ni": -2.0354}
         fig = periodic_table_heatmap(random_data)
diff --git a/tests/vis/test_plotters.py b/tests/vis/test_plotters.py
index 87311cc4d66..7fc28013d07 100644
--- a/tests/vis/test_plotters.py
+++ b/tests/vis/test_plotters.py
@@ -8,14 +8,14 @@
 from monty.json import MontyDecoder
 
 from pymatgen.analysis.xas.spectrum import XAS
-from pymatgen.util.testing import TEST_FILES_DIR, PymatgenTest
+from pymatgen.util.testing import TEST_FILES_DIR
 from pymatgen.vis.plotters import SpectrumPlotter
 
 with open(f"{TEST_FILES_DIR}/analysis/spectrum_test/LiCoO2_k_xanes.json") as file:
     spect_data_dict = json.load(file, cls=MontyDecoder)
 
 
-class TestSpectrumPlotter(PymatgenTest):
+class TestSpectrumPlotter:
     def setUp(self):
         self.xanes = XAS.from_dict(spect_data_dict)