From 506f3b5eda7d3de44ea91542cb2e8d74ce18489b Mon Sep 17 00:00:00 2001
From: "pre-commit-ci[bot]"
 <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Date: Mon, 16 Dec 2024 23:47:15 +0000
Subject: [PATCH 1/3] [pre-commit.ci] pre-commit autoupdate
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

updates:
- [github.com/astral-sh/ruff-pre-commit: v0.8.2 → v0.8.3](https://github.com/astral-sh/ruff-pre-commit/compare/v0.8.2...v0.8.3)
---
 .pre-commit-config.yaml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index 1e0a12eb..ea69ffe6 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -11,7 +11,7 @@ repos:
     exclude: ^example/AlN-LDA/
 
 - repo: https://github.com/astral-sh/ruff-pre-commit
-  rev: v0.8.2
+  rev: v0.8.3
   hooks:
   - id: ruff
     args: [ "--fix", "--show-fixes" ]

From 4341f8c6c63e8507c35c12eb5ae8042998682373 Mon Sep 17 00:00:00 2001
From: Atsushi Togo <atz.togo@gmail.com>
Date: Wed, 18 Dec 2024 13:23:10 +0900
Subject: [PATCH 2/3] Change dtype=int_ to long

---
 phono3py/api_isotope.py                  |   2 +-
 phono3py/api_phono3py.py                 |  16 +--
 phono3py/conductivity/base.py            |  18 +--
 phono3py/conductivity/direct_solution.py |  10 +-
 phono3py/conductivity/rta.py             |   2 +-
 phono3py/cui/kaccum_script.py            |   8 +-
 phono3py/cui/phono3py_script.py          |   2 +-
 phono3py/cui/triplets_info.py            |  42 ++++---
 phono3py/file_IO.py                      |   4 +-
 phono3py/other/isotope.py                |   8 +-
 phono3py/other/kaccum.py                 |  18 +--
 phono3py/other/tetrahedron_method.py     |  28 ++---
 phono3py/phonon/grid.py                  | 150 +++++++++++------------
 phono3py/phonon/solver.py                |   6 +-
 phono3py/phonon3/collision_matrix.py     |   6 +-
 phono3py/phonon3/fc3.py                  |  32 ++---
 phono3py/phonon3/interaction.py          |  22 ++--
 phono3py/phonon3/joint_dos.py            |   8 +-
 phono3py/phonon3/triplets.py             |  67 +++++-----
 test/phonon/test_grid.py                 |   2 +-
 20 files changed, 230 insertions(+), 221 deletions(-)

diff --git a/phono3py/api_isotope.py b/phono3py/api_isotope.py
index de7b87eb..f0a93f4b 100644
--- a/phono3py/api_isotope.py
+++ b/phono3py/api_isotope.py
@@ -107,7 +107,7 @@ def run(self, grid_points, lang="C"):
             (len(self._sigmas), len(grid_points), len(self._iso.band_indices)),
             dtype="double",
         )
-        self._grid_points = np.array(grid_points, dtype="int_")
+        self._grid_points = np.array(grid_points, dtype="long")
 
         for j, gp in enumerate(grid_points):
             self._iso.set_grid_point(gp)
diff --git a/phono3py/api_phono3py.py b/phono3py/api_phono3py.py
index f6b37d2f..7138b90a 100644
--- a/phono3py/api_phono3py.py
+++ b/phono3py/api_phono3py.py
@@ -234,14 +234,14 @@ def __init__(
         # Create supercell and primitive cell
         self._unitcell = unitcell
         self._supercell_matrix = np.array(
-            shape_supercell_matrix(supercell_matrix), dtype="int_", order="C"
+            shape_supercell_matrix(supercell_matrix), dtype="long", order="C"
         )
         pmat = self._determine_primitive_matrix(primitive_matrix)
         self._primitive_matrix = pmat
         self._nac_params = None
         if phonon_supercell_matrix is not None:
             self._phonon_supercell_matrix = np.array(
-                shape_supercell_matrix(phonon_supercell_matrix), dtype="int_", order="C"
+                shape_supercell_matrix(phonon_supercell_matrix), dtype="long", order="C"
             )
         else:
             self._phonon_supercell_matrix = None
@@ -538,7 +538,7 @@ def supercell_matrix(self) -> np.ndarray:
 
         ndarray
             Supercell matrix with respect to unit cell.
-            shape=(3, 3), dtype='int_', order='C'
+            shape=(3, 3), dtype='long', order='C'
 
         """
         return self._supercell_matrix
@@ -549,7 +549,7 @@ def phonon_supercell_matrix(self) -> Optional[np.ndarray]:
 
         ndarray
             Supercell matrix with respect to unit cell.
-            shape=(3, 3), dtype='int_', order='C'
+            shape=(3, 3), dtype='long', order='C'
 
         """
         return self._phonon_supercell_matrix
@@ -743,10 +743,10 @@ def band_indices(self, band_indices):
     def _set_band_indices(self, band_indices=None):
         if band_indices is None:
             num_band = len(self._primitive) * 3
-            self._band_indices = [np.arange(num_band, dtype="int_")]
+            self._band_indices = [np.arange(num_band, dtype="long")]
         else:
-            self._band_indices = [np.array(bi, dtype="int_") for bi in band_indices]
-        self._band_indices_flatten = np.hstack(self._band_indices).astype("int_")
+            self._band_indices = [np.array(bi, dtype="long") for bi in band_indices]
+        self._band_indices_flatten = np.hstack(self._band_indices).astype("long")
 
     @property
     def masses(self) -> np.ndarray:
@@ -1948,7 +1948,7 @@ def run_thermal_conductivity(
             List of grid point indices where mode thermal conductivities are
             calculated. With None, all the grid points that are necessary
             for thermal conductivity are set internally.
-            shape(num_grid_points, ), dtype='int_'.
+            shape(num_grid_points, ), dtype='long'.
         boundary_mfp : float, optiona, default is None
             Mean free path in micrometre to calculate simple boundary
             scattering contribution to thermal conductivity.
diff --git a/phono3py/conductivity/base.py b/phono3py/conductivity/base.py
index 24478392..4e750b16 100644
--- a/phono3py/conductivity/base.py
+++ b/phono3py/conductivity/base.py
@@ -281,7 +281,7 @@ def __init__(
         grid_points : array_like or None, optional
             Grid point indices in BZgrid. When None, ir-grid points are searched
             internally. Default is None.
-            shape=(grid_points, ), dtype='int_'.
+            shape=(grid_points, ), dtype='long'.
         temperatures : array_like, optional, default is None
             Temperatures at which thermal conductivity is calculated.
             shape=(temperature_points, ), dtype='double'.
@@ -676,7 +676,7 @@ def _get_point_operations(self) -> Tuple[np.ndarray, np.ndarray]:
         -------
         point_operations : ndarray
             Operations in reduced coordinates.
-            shape=(num_operations, 3, 3), dtype='int_'
+            shape=(num_operations, 3, 3), dtype='long'
         rotations_cartesian : ndarray
             Operations in Cartesian coordinates.
             shape=(num_operations, 3, 3), dtype='double'
@@ -684,7 +684,7 @@ def _get_point_operations(self) -> Tuple[np.ndarray, np.ndarray]:
         """
         if not self._is_kappa_star:
             point_operations = np.array(
-                [np.eye(3, dtype="int_")], dtype="int_", order="C"
+                [np.eye(3, dtype="long")], dtype="long", order="C"
             )
             rotations_cartesian = np.array(
                 [np.eye(3, dtype="double")], dtype="double", order="C"
@@ -702,10 +702,10 @@ def _get_grid_info(self, grid_points) -> Tuple[np.ndarray, np.ndarray, np.ndarra
         -------
         grid_points : ndarray
             Grid point indices in BZ-grid to be iterated over.
-            shape=(len(grid_points),), dtype='int_'
+            shape=(len(grid_points),), dtype='long'
         ir_grid_points : ndarray
             Irreducible grid points in BZ-grid on regular grid.
-            shape=(len(ir_grid_points),), dtype='int_'
+            shape=(len(ir_grid_points),), dtype='long'
         grid_weights : ndarray
             Grid weights of `grid_points`. If grid symmetry is not broken,
             these values are equivalent to numbers of k-star arms.
@@ -713,13 +713,13 @@ def _get_grid_info(self, grid_points) -> Tuple[np.ndarray, np.ndarray, np.ndarra
         """
         ir_grid_points, grid_weights = self._get_ir_grid_points(grid_points)
         if grid_points is not None:  # Specify grid points
-            _grid_points = np.array(grid_points, dtype="int_")
+            _grid_points = np.array(grid_points, dtype="long")
             _ir_grid_points = ir_grid_points
             _grid_weights = grid_weights
         elif not self._is_kappa_star:  # All grid points
             _grid_points = self._pp.bz_grid.grg2bzg
             _ir_grid_points = _grid_points
-            _grid_weights = np.ones(len(_grid_points), dtype="int_")
+            _grid_weights = np.ones(len(_grid_points), dtype="long")
         else:  # Automatic sampling
             _grid_points = ir_grid_points
             _ir_grid_points = ir_grid_points
@@ -777,7 +777,7 @@ def _get_ir_grid_points(self, grid_points):
             self._pp.bz_grid
         )
         ir_grid_points = np.array(
-            self._pp.bz_grid.grg2bzg[ir_grid_points], dtype="int_"
+            self._pp.bz_grid.grg2bzg[ir_grid_points], dtype="long"
         )
         if grid_points is None:
             grid_weights = ir_grid_weights
@@ -787,7 +787,7 @@ def _get_ir_grid_points(self, grid_points):
                 weights[gp] += 1
             grid_weights = np.array(
                 weights[ir_grid_map[self._pp.bz_grid.bzg2grg[grid_points]]],
-                dtype="int_",
+                dtype="long",
             )
 
         return ir_grid_points, grid_weights
diff --git a/phono3py/conductivity/direct_solution.py b/phono3py/conductivity/direct_solution.py
index 8477e089..8e3ec348 100644
--- a/phono3py/conductivity/direct_solution.py
+++ b/phono3py/conductivity/direct_solution.py
@@ -287,7 +287,7 @@ def _set_kappa_reducible_colmat(self, kappa, mode_kappa, i_sigma, i_temp, weight
     def _get_rot_grid_points(self):
         num_ir_grid_points = len(self._ir_grid_points)
         rot_grid_points = np.zeros(
-            (num_ir_grid_points, len(self._point_operations)), dtype="int_"
+            (num_ir_grid_points, len(self._point_operations)), dtype="long"
         )
         if self._is_kappa_star:
             rotations = self._pp.bz_grid.rotations  # rotations of GR-grid
@@ -530,10 +530,10 @@ def _prepare_collision_matrix(self):
                 self._average_collision_matrix_by_degeneracy()
                 num_mesh_points = np.prod(self._pp.mesh_numbers)
                 num_rot = len(self._point_operations)
-                rot_grid_points = np.zeros((num_rot, num_mesh_points), dtype="int_")
+                rot_grid_points = np.zeros((num_rot, num_mesh_points), dtype="long")
                 # Ir-grid points and rot_grid_points in generalized regular grid
                 ir_gr_grid_points = np.array(
-                    self._pp.bz_grid.bzg2grg[self._ir_grid_points], dtype="int_"
+                    self._pp.bz_grid.bzg2grg[self._ir_grid_points], dtype="long"
                 )
                 for i in range(num_mesh_points):
                     rot_grid_points[:, i] = self._pp.bz_grid.bzg2grg[
@@ -544,7 +544,7 @@ def _prepare_collision_matrix(self):
                 self._expand_reducible_collisions(ir_gr_grid_points, rot_grid_points)
                 self._expand_local_values(ir_gr_grid_points, rot_grid_points)
             self._combine_reducible_collisions()
-            weights = np.ones(np.prod(self._pp.mesh_numbers), dtype="int_")
+            weights = np.ones(np.prod(self._pp.mesh_numbers), dtype="long")
             self._symmetrize_collision_matrix()
         else:
             self._combine_collisions()
@@ -647,7 +647,7 @@ def _get_weights(self):
         self._rot_grid_points : ndarray
             Grid points generated by applying point group to ir-grid-points
             in BZ-grid.
-            shape=(ir_grid_points, point_operations), dtype='int_'
+            shape=(ir_grid_points, point_operations), dtype='long'
 
         r_gps : grid points of arms of k-star with duplicates
             len(r_gps) == order of crystallographic point group
diff --git a/phono3py/conductivity/rta.py b/phono3py/conductivity/rta.py
index ac26f057..4edf98c0 100644
--- a/phono3py/conductivity/rta.py
+++ b/phono3py/conductivity/rta.py
@@ -372,7 +372,7 @@ class instance.
                     collisions,
                     np.array(
                         np.dot(tetrahedra, self._pp.bz_grid.P.T),
-                        dtype="int_",
+                        dtype="long",
                         order="C",
                     ),
                     self._frequencies,
diff --git a/phono3py/cui/kaccum_script.py b/phono3py/cui/kaccum_script.py
index 4eee31e5..b32d327f 100644
--- a/phono3py/cui/kaccum_script.py
+++ b/phono3py/cui/kaccum_script.py
@@ -79,7 +79,7 @@ def _get_ir_grid_info(bz_grid: BZGrid, weights, qpoints=None, ir_grid_points=Non
     -------
     ir_grid_points : ndarray
         Ir-grid point indices in BZ-grid.
-        shape=(ir_grid_points, ), dtype='int_'
+        shape=(ir_grid_points, ), dtype='long'
     ir_grid_map : ndarray, optional, default=None
         Mapping table to ir-grid point indices in GR-grid.
 
@@ -289,9 +289,9 @@ def main():
         f_kappa = h5py.File(args.filenames[0], "r")
 
     if "grid_matrix" in f_kappa:
-        mesh = np.array(f_kappa["grid_matrix"][:], dtype="int_")
+        mesh = np.array(f_kappa["grid_matrix"][:], dtype="long")
     else:
-        mesh = np.array(f_kappa["mesh"][:], dtype="int_")
+        mesh = np.array(f_kappa["mesh"][:], dtype="long")
     if "temperature" in f_kappa:
         temperatures = f_kappa["temperature"][:]
     else:
@@ -308,7 +308,7 @@ def main():
         frequencies = np.array(f_kappa["frequency"][ir_grid_points_BZ], dtype="double")
     else:
         frequencies = f_kappa["frequency"][:]
-        ir_weights = np.ones(len(frequencies), dtype="int_")
+        ir_weights = np.ones(len(frequencies), dtype="long")
     primitive_symmetry = Symmetry(primitive)
     bz_grid = BZGrid(
         mesh,
diff --git a/phono3py/cui/phono3py_script.py b/phono3py/cui/phono3py_script.py
index c5d77627..d1cf1b2a 100644
--- a/phono3py/cui/phono3py_script.py
+++ b/phono3py/cui/phono3py_script.py
@@ -877,7 +877,7 @@ def init_phph_interaction(
     if settings.write_phonon:
         freqs, eigvecs, grid_address = phono3py.get_phonon_data()
         ir_grid_points, ir_grid_weights, _ = get_ir_grid_points(bz_grid)
-        ir_grid_points = np.array(bz_grid.grg2bzg[ir_grid_points], dtype="int_")
+        ir_grid_points = np.array(bz_grid.grg2bzg[ir_grid_points], dtype="long")
         filename = write_phonon_to_hdf5(
             freqs,
             eigvecs,
diff --git a/phono3py/cui/triplets_info.py b/phono3py/cui/triplets_info.py
index 1e85bbc9..5cf7a546 100644
--- a/phono3py/cui/triplets_info.py
+++ b/phono3py/cui/triplets_info.py
@@ -34,23 +34,27 @@
 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
+from collections.abc import Sequence
+from typing import Optional, Union
+
 import numpy as np
+from phonopy.structure.atoms import PhonopyAtoms
 
 from phono3py.file_IO import write_grid_address_to_hdf5, write_ir_grid_points
-from phono3py.phonon.grid import get_ir_grid_points
+from phono3py.phonon.grid import BZGrid, get_ir_grid_points
 from phono3py.phonon3.triplets import get_triplets_at_q
 
 
 def write_grid_points(
-    primitive,
-    bz_grid,
-    band_indices=None,
-    sigmas=None,
-    temperatures=None,
-    is_kappa_star=True,
-    is_lbte=False,
-    compression="gzip",
-    filename=None,
+    primitive: PhonopyAtoms,
+    bz_grid: BZGrid,
+    band_indices: Optional[Union[Sequence, np.ndarray]] = None,
+    sigmas: Optional[Union[Sequence, np.ndarray]] = None,
+    temperatures: Optional[Union[Sequence, np.ndarray]] = None,
+    is_kappa_star: bool = True,
+    is_lbte: bool = False,
+    compression: Union[str, int] = "gzip",
+    filename: bool = None,
 ):
     """Write grid points into files."""
     ir_grid_points, ir_grid_weights = _get_ir_grid_points(
@@ -103,7 +107,11 @@ def write_grid_points(
 
 
 def show_num_triplets(
-    primitive, bz_grid, band_indices=None, grid_points=None, is_kappa_star=True
+    primitive: PhonopyAtoms,
+    bz_grid: BZGrid,
+    band_indices: Optional[Union[Sequence, np.ndarray]] = None,
+    grid_points: Optional[Union[Sequence, np.ndarray]] = None,
+    is_kappa_star: bool = True,
 ):
     """Show numbers of triplets at grid points."""
     tp_nums = _TripletsNumbers(bz_grid, is_kappa_star=is_kappa_star)
@@ -131,7 +139,7 @@ def show_num_triplets(
 
 
 class _TripletsNumbers:
-    def __init__(self, bz_grid, is_kappa_star=True):
+    def __init__(self, bz_grid: BZGrid, is_kappa_star: bool = True):
         self._bz_grid = bz_grid
         (
             self.ir_grid_points,
@@ -143,19 +151,19 @@ def get_number_of_triplets(self, gp):
         return num_triplets
 
 
-def _get_ir_grid_points(bz_grid, is_kappa_star=True):
+def _get_ir_grid_points(bz_grid: BZGrid, is_kappa_star: bool = True):
     if is_kappa_star:
         ir_grid_points, ir_grid_weights, _ = get_ir_grid_points(bz_grid)
-        ir_grid_points = np.array(bz_grid.grg2bzg[ir_grid_points], dtype="int_")
+        ir_grid_points = np.array(bz_grid.grg2bzg[ir_grid_points], dtype="long")
     else:
         ir_grid_points = np.array(
-            bz_grid.grg2bzg[: np.prod(bz_grid.D_diag)], dtype="int_", order="C"
+            bz_grid.grg2bzg[: np.prod(bz_grid.D_diag)], dtype="long", order="C"
         )
-        ir_grid_weights = np.ones(len(ir_grid_points), dtype="int_")
+        ir_grid_weights = np.ones(len(ir_grid_points), dtype="long")
 
     return ir_grid_points, ir_grid_weights
 
 
-def _get_number_of_triplets(bz_grid, grid_point, swappable=True):
+def _get_number_of_triplets(bz_grid: BZGrid, grid_point: int, swappable: bool = True):
     triplets_at_q = get_triplets_at_q(grid_point, bz_grid, swappable=swappable)[0]
     return len(triplets_at_q)
diff --git a/phono3py/file_IO.py b/phono3py/file_IO.py
index 672bc3d6..e8f6fb5e 100644
--- a/phono3py/file_IO.py
+++ b/phono3py/file_IO.py
@@ -438,7 +438,7 @@ def write_grid_address_to_hdf5(
     mesh,
     grid_mapping_table,
     bz_grid=None,
-    compression="gzip",
+    compression: Union[str, int] = "gzip",
     filename=None,
 ):
     """Write grid addresses to grid_address.hdf5."""
@@ -714,7 +714,7 @@ def write_spectral_function_to_hdf5(
     if all_band_exist:
         _band_indices = None
     else:
-        _band_indices = np.hstack(band_indices).astype("int_")
+        _band_indices = np.hstack(band_indices).astype("long")
     suffix = _get_filename_suffix(
         mesh, grid_point=grid_point, band_indices=_band_indices, sigma=sigma
     )
diff --git a/phono3py/other/isotope.py b/phono3py/other/isotope.py
index 275c6516..18c8fa27 100644
--- a/phono3py/other/isotope.py
+++ b/phono3py/other/isotope.py
@@ -136,9 +136,9 @@ def __init__(
 
         num_band = len(self._primitive) * 3
         if band_indices is None:
-            self._band_indices = np.arange(num_band, dtype="int_")
+            self._band_indices = np.arange(num_band, dtype="long")
         else:
-            self._band_indices = np.array(band_indices, dtype="int_")
+            self._band_indices = np.array(band_indices, dtype="long")
 
         if self._bz_grid is None:
             primitive_symmetry = Symmetry(self._primitive, self._symprec)
@@ -153,7 +153,7 @@ def __init__(
     def set_grid_point(self, grid_point):
         """Initialize grid points."""
         self._grid_point = grid_point
-        self._grid_points = np.arange(len(self._bz_grid.addresses), dtype="int_")
+        self._grid_points = np.arange(len(self._bz_grid.addresses), dtype="long")
 
         if self._phonon_done is None:
             self._allocate_phonon()
@@ -319,7 +319,7 @@ def _set_integration_weights_py(self):
                 self._bz_grid.addresses,
                 np.array(
                     np.dot(thm.tetrahedra, self._bz_grid.P.T),
-                    dtype="int_",
+                    dtype="long",
                     order="C",
                 ),
                 self._bz_grid.grg2bzg,
diff --git a/phono3py/other/kaccum.py b/phono3py/other/kaccum.py
index 86811cc2..d30e8a35 100644
--- a/phono3py/other/kaccum.py
+++ b/phono3py/other/kaccum.py
@@ -76,17 +76,17 @@ def __init__(
         ir_grid_points : ndarray
             Irreducible grid point indices in GR-grid (as obtained by
             get_ir_grid_points).
-            shape=(num_ir_grid_points, ), dtype='int_'
+            shape=(num_ir_grid_points, ), dtype='long'
         ir_grid_weights : ndarray
             Weights of irreducible grid points. Its sum is the number of grid
             points in GR-grid (prod(D_diag)) (as obtained by
             get_ir_grid_points).
-            shape=(num_ir_grid_points, ), dtype='int_'
+            shape=(num_ir_grid_points, ), dtype='long'
         ir_grid_map : ndarray
             Index mapping table to irreducible grid points from all grid points
             in GR-grid such as, [0, 0, 2, 3, 3, ...]. (as obtained by
             get_ir_grid_points).
-            shape=(prod(D_diag), ), dtype='int_'
+            shape=(prod(D_diag), ), dtype='long'
         frequency_points : array_like, optional, default=None
             This is used as the frequency points. When None, frequency points
             are created from `num_sampling_points`.
@@ -120,7 +120,7 @@ def __init__(
             bz_grid.bzg2grg, _ir_grid_map, _ir_grid_points
         )
         if ir_grid_weights is None:
-            grid_weights = np.ones(mode_kappa.shape[1], dtype="int_")
+            grid_weights = np.ones(mode_kappa.shape[1], dtype="long")
         else:
             grid_weights = ir_grid_weights
         for j, function in enumerate(("J", "I")):
@@ -164,13 +164,13 @@ def _get_bzgp2irgp_map(self, bzg2grg, ir_grid_map, ir_grid_points):
         ----------
         bzg2grg : ndarray
             Mapping table from BZ-grid to GR-grid.
-            shape=(len(all-BZ-grid-points), ), dtype='int_'
+            shape=(len(all-BZ-grid-points), ), dtype='long'
         ir_grid_map : ndarray
             Mapping table from all grid points to ir-grid points in GR-grid.
-            shape=(np.prod(D_diag), ), dtype='int_'
+            shape=(np.prod(D_diag), ), dtype='long'
         ir_grid_points : ndarray
             Irreducible grid points in GR-grid. shape=(num_ir_grid_points, ),
-            dtype='int_'
+            dtype='long'
 
         Returns
         -------
@@ -184,7 +184,7 @@ def _get_bzgp2irgp_map(self, bzg2grg, ir_grid_map, ir_grid_points):
         # ir-grid points in GR-grid to the index of unique grid points.
         gp_map = {j: i for i, j in enumerate(unique_gps)}
         bzgp2irgp_map = np.array(
-            [gp_map[ir_grid_map[grgp]] for grgp in bzg2grg], dtype="int_"
+            [gp_map[ir_grid_map[grgp]] for grgp in bzg2grg], dtype="long"
         )
         return bzgp2irgp_map
 
@@ -210,7 +210,7 @@ def __init__(
             shape=(ir_grid_points, num_band), dtype='double'
         ir_grid_weights : ndarray
             Grid point weights at ir-grid points.
-            shape=(ir_grid_points, ), dtype='int_'
+            shape=(ir_grid_points, ), dtype='long'
         sigma : float
             Smearing width.
         num_sampling_points : int, optional, default=100
diff --git a/phono3py/other/tetrahedron_method.py b/phono3py/other/tetrahedron_method.py
index 83a280fc..cb3c9920 100644
--- a/phono3py/other/tetrahedron_method.py
+++ b/phono3py/other/tetrahedron_method.py
@@ -57,23 +57,23 @@ def get_unique_grid_points(grid_points, bz_grid: BZGrid):
     -------
     ndarray
         Unique grid points on tetrahedron vertices around input grid points.
-        shape=(unique_grid_points, ), dtype='int_'.
+        shape=(unique_grid_points, ), dtype='long'.
 
     """
     import phono3py._phono3py as phono3c
 
-    if _check_ndarray_state(grid_points, "int_"):
+    if _check_ndarray_state(grid_points, "long"):
         _grid_points = grid_points
     else:
-        _grid_points = np.array(grid_points, dtype="int_")
+        _grid_points = np.array(grid_points, dtype="long")
     thm = TetrahedronMethod(bz_grid.microzone_lattice)
     unique_vertices = np.array(
         np.dot(thm.get_unique_tetrahedra_vertices(), bz_grid.P.T),
-        dtype="int_",
+        dtype="long",
         order="C",
     )
     neighboring_grid_points = np.zeros(
-        len(unique_vertices) * len(_grid_points), dtype="int_"
+        len(unique_vertices) * len(_grid_points), dtype="long"
     )
     phono3c.neighboring_grid_points(
         neighboring_grid_points,
@@ -84,7 +84,7 @@ def get_unique_grid_points(grid_points, bz_grid: BZGrid):
         bz_grid.gp_map,
         bz_grid.store_dense_gp_map * 1 + 1,
     )
-    unique_grid_points = np.array(np.unique(neighboring_grid_points), dtype="int_")
+    unique_grid_points = np.array(np.unique(neighboring_grid_points), dtype="long")
     return unique_grid_points
 
 
@@ -111,7 +111,7 @@ def get_integration_weights(
         Grid information in reciprocal space.
     grid_points : array_like, optional, default=None
         Grid point indices in BZ-grid. If None, all regular grid points in
-        BZ-grid. shape=(grid_points, ), dtype='int_'
+        BZ-grid. shape=(grid_points, ), dtype='long'
     bzgp2irgp_map : array_like, optional, default=None
         Grid point index mapping from bz_grid to index of the first dimension of
         `grid_values` array, i.e., usually irreducible grid point count.
@@ -131,15 +131,15 @@ def get_integration_weights(
         np.dot(
             get_tetrahedra_relative_grid_address(bz_grid.microzone_lattice), bz_grid.P.T
         ),
-        dtype="int_",
+        dtype="long",
         order="C",
     )
     if grid_points is None:
         _grid_points = bz_grid.grg2bzg
-    elif _check_ndarray_state(grid_points, "int_"):
+    elif _check_ndarray_state(grid_points, "long"):
         _grid_points = grid_points
     else:
-        _grid_points = np.array(grid_points, dtype="int_")
+        _grid_points = np.array(grid_points, dtype="long")
     if _check_ndarray_state(grid_values, "double"):
         _grid_values = grid_values
     else:
@@ -149,11 +149,11 @@ def get_integration_weights(
     else:
         _sampling_points = np.array(sampling_points, dtype="double")
     if bzgp2irgp_map is None:
-        _bzgp2irgp_map = np.arange(len(grid_values), dtype="int_")
-    elif _check_ndarray_state(bzgp2irgp_map, "int_"):
+        _bzgp2irgp_map = np.arange(len(grid_values), dtype="long")
+    elif _check_ndarray_state(bzgp2irgp_map, "long"):
         _bzgp2irgp_map = bzgp2irgp_map
     else:
-        _bzgp2irgp_map = np.array(bzgp2irgp_map, dtype="int_")
+        _bzgp2irgp_map = np.array(bzgp2irgp_map, dtype="long")
 
     num_grid_points = len(_grid_points)
     num_band = _grid_values.shape[1]
@@ -188,7 +188,7 @@ def get_tetrahedra_relative_grid_address(microzone_lattice):
     """
     import phono3py._phono3py as phono3c
 
-    relative_grid_address = np.zeros((24, 4, 3), dtype="int_", order="C")
+    relative_grid_address = np.zeros((24, 4, 3), dtype="long", order="C")
     phono3c.tetrahedra_relative_grid_address(
         relative_grid_address, np.array(microzone_lattice, dtype="double", order="C")
     )
diff --git a/phono3py/phonon/grid.py b/phono3py/phonon/grid.py
index 1aa34fc6..c34bcc9f 100644
--- a/phono3py/phonon/grid.py
+++ b/phono3py/phonon/grid.py
@@ -156,7 +156,7 @@ def __init__(
         """Init method.
 
         mesh : array_like or float
-            Mesh numbers or length. shape=(3,), dtype='int_'
+            Mesh numbers or length. shape=(3,), dtype='long'
         reciprocal_lattice : array_like
             Reciprocal primitive basis vectors given as column vectors shape=(3,
             3), dtype='double', order='C'
@@ -174,7 +174,7 @@ def __init__(
         is_shift : array_like or None, optional
             [0, 0, 0] (or [False, False, False]) gives Gamma center mesh and
             value 1 (or True) gives half mesh shift along the basis vectors.
-            Default is None. dtype='int_', shape=(3,)
+            Default is None. dtype='long', shape=(3,)
         is_time_reveral : bool, optional
             Inversion symmetry is included in reciprocal point group. Default is
             True.
@@ -205,9 +205,9 @@ def __init__(
         self._addresses = None
         self._gp_map = None
         self._grid_matrix = None
-        self._D_diag = np.ones(3, dtype="int_")
-        self._Q = np.eye(3, dtype="int_", order="C")
-        self._P = np.eye(3, dtype="int_", order="C")
+        self._D_diag = np.ones(3, dtype="long")
+        self._Q = np.eye(3, dtype="long", order="C")
+        self._P = np.eye(3, dtype="long", order="C")
         self._QDinv = None
         self._microzone_lattice = None
         self._rotations = None
@@ -237,7 +237,7 @@ def D_diag(self):
 
         This corresponds to the mesh numbers in transformed reciprocal
         basis vectors.
-        shape=(3,), dtype='int_'
+        shape=(3,), dtype='long'
 
         """
         return self._D_diag
@@ -247,7 +247,7 @@ def P(self):
         """Left unimodular matrix after SNF: D=PAQ.
 
         Left unimodular matrix after SNF: D=PAQ.
-        shape=(3, 3), dtype='int_', order='C'.
+        shape=(3, 3), dtype='long', order='C'.
 
         """
         return self._P
@@ -257,7 +257,7 @@ def Q(self):
         """Right unimodular matrix after SNF: D=PAQ.
 
         Right unimodular matrix after SNF: D=PAQ.
-        shape=(3, 3), dtype='int_', order='C'.
+        shape=(3, 3), dtype='long', order='C'.
 
         """
         return self._Q
@@ -276,9 +276,9 @@ def QDinv(self):
     def PS(self):
         """Integer shift vectors of GRGrid."""
         if self._is_shift is None:
-            return np.zeros(3, dtype="int_")
+            return np.zeros(3, dtype="long")
         else:
-            return np.array(np.dot(self.P, self._is_shift), dtype="int_")
+            return np.array(np.dot(self.P, self._is_shift), dtype="long")
 
     @property
     def grid_matrix(self):
@@ -286,7 +286,7 @@ def grid_matrix(self):
 
         Grid generating matrix used for SNF.
         When SNF is used, ndarray, otherwise None.
-        shape=(3, 3), dtype='int_', order='C'.
+        shape=(3, 3), dtype='long', order='C'.
 
         """
         return self._grid_matrix
@@ -298,7 +298,7 @@ def addresses(self):
         Integer grid address of the points in Brillouin zone including
         surface. There are two types of address order by either
         `store_dense_gp_map` is True or False.
-        shape=(np.prod(D_diag) + some on surface, 3), dtype='int_', order='C'.
+        shape=(np.prod(D_diag) + some on surface, 3), dtype='long', order='C'.
 
         """
         return self._addresses
@@ -324,7 +324,7 @@ def bzg2grg(self):
         """Transform grid point indices from BZG to GRG.
 
         Grid index mapping table from BZGrid to GRgrid.
-        shape=(len(addresses), ), dtype='int_'.
+        shape=(len(addresses), ), dtype='long'.
 
         Equivalent to
             get_grid_point_from_address(
@@ -339,7 +339,7 @@ def grg2bzg(self):
 
         Grid index mapping table from GRgrid to BZGrid. Unique one
         of translationally equivalent grid points in BZGrid is chosen.
-        shape=(prod(D_diag), ), dtype='int_'.
+        shape=(prod(D_diag), ), dtype='long'.
 
         """
         return self._grg2bzg
@@ -370,7 +370,7 @@ def rotations(self):
         Rotation matrices for GR-grid addresses (g) defined as g'=Rg. This can
         be different from ``reciprocal_operations`` when GR-grid is used because
         grid addresses are defined on an oblique lattice.
-        shape=(rotations, 3, 3), dtype='int_', order='C'.
+        shape=(rotations, 3, 3), dtype='long', order='C'.
 
         """
         return self._rotations
@@ -386,7 +386,7 @@ def reciprocal_operations(self):
 
         Reciprocal space rotation matrices in fractional coordinates defined as
         q'=Rq.
-        shape=(rotations, 3, 3), dtype='int_', order='C'.
+        shape=(rotations, 3, 3), dtype='long', order='C'.
 
         """
         return self._reciprocal_operations
@@ -411,7 +411,7 @@ def get_indices_from_addresses(self, addresses):
             Grid point indices corresponding to the grid addresses. Each
             returned grid point index is one of those of the
             translationally equivalent grid points.
-            shape=(n, ), dtype='int_' when multiple addresses are given.
+            shape=(n, ), dtype='long' when multiple addresses are given.
             Otherwise one integer value is returned.
 
         """
@@ -423,7 +423,7 @@ def get_indices_from_addresses(self, addresses):
             )
 
         gps = [get_grid_point_from_address(adrs, self._D_diag) for adrs in addresses]
-        return np.array(self._grg2bzg[gps], dtype="int_")
+        return np.array(self._grg2bzg[gps], dtype="long")
 
     def _generate_grid(
         self, mesh, use_grg=False, force_SNF=False, SNF_coordinates="reciprocal"
@@ -454,9 +454,9 @@ def _set_bz_grid(self):
             store_dense_gp_map=self._store_dense_gp_map,
         )
         if self._store_dense_gp_map:
-            self._grg2bzg = np.array(self._gp_map[:-1], dtype="int_")
+            self._grg2bzg = np.array(self._gp_map[:-1], dtype="long")
         else:
-            self._grg2bzg = np.arange(np.prod(self._D_diag), dtype="int_")
+            self._grg2bzg = np.arange(np.prod(self._D_diag), dtype="long")
 
         self._QDinv = np.array(
             self.Q * (1 / self.D_diag.astype("double")), dtype="double", order="C"
@@ -477,17 +477,17 @@ def _set_rotations(self):
         import phono3py._recgrid as recgrid
 
         if self._symmetry_dataset is None:
-            direct_rotations = np.eye(3, dtype="int_", order="C").reshape(1, 3, 3)
+            direct_rotations = np.eye(3, dtype="long", order="C").reshape(1, 3, 3)
         else:
             direct_rotations = np.array(
-                self._symmetry_dataset.rotations, dtype="int_", order="C"
+                self._symmetry_dataset.rotations, dtype="long", order="C"
             )
-        rec_rotations = np.zeros((48, 3, 3), dtype="int_", order="C")
+        rec_rotations = np.zeros((48, 3, 3), dtype="long", order="C")
         num_rec_rot = recgrid.reciprocal_rotations(
             rec_rotations, direct_rotations, self._is_time_reversal
         )
         self._reciprocal_operations = np.array(
-            rec_rotations[:num_rec_rot], dtype="int_", order="C"
+            rec_rotations[:num_rec_rot], dtype="long", order="C"
         )
         self._rotations_cartesian = np.array(
             [
@@ -498,7 +498,7 @@ def _set_rotations(self):
             order="C",
         )
         self._rotations = np.zeros(
-            self._reciprocal_operations.shape, dtype="int_", order="C"
+            self._reciprocal_operations.shape, dtype="long", order="C"
         )
         if not recgrid.transform_rotations(
             self._rotations, self._reciprocal_operations, self._D_diag, self._Q
@@ -550,8 +550,8 @@ def __init__(
             Mesh numbers or length. With float number, either conventional or
             generalized regular grid is computed depending on the given flags
             (`use_grg`, `force_SNF`). Given ndarry with
-                shape=(3,), dtype='int_': conventional regular grid shape=(3,
-                3), dtype='int_': generalized regular grid
+                shape=(3,), dtype='long': conventional regular grid shape=(3,
+                3), dtype='long': generalized regular grid
         lattice : array_like
             Primitive basis vectors in direct space given as row vectors.
             shape=(3, 3), dtype='double', order='C'
@@ -577,9 +577,9 @@ def __init__(
         self._mesh = mesh
         self._lattice = lattice
         self._grid_matrix = None
-        self._D_diag = np.ones(3, dtype="int_")
-        self._Q = np.eye(3, dtype="int_", order="C")
-        self._P = np.eye(3, dtype="int_", order="C")
+        self._D_diag = np.ones(3, dtype="long")
+        self._Q = np.eye(3, dtype="long", order="C")
+        self._P = np.eye(3, dtype="long", order="C")
 
         self._set_mesh_numbers(
             mesh,
@@ -596,7 +596,7 @@ def grid_matrix(self):
 
         Grid generating matrix used for SNF.
         When SNF is used, ndarray, otherwise None.
-        shape=(3, 3), dtype='int_', order='C'.
+        shape=(3, 3), dtype='long', order='C'.
 
         """
         return self._grid_matrix
@@ -607,7 +607,7 @@ def D_diag(self):
 
         This corresponds to the mesh numbers in transformed reciprocal
         basis vectors.
-        shape=(3,), dtype='int_'
+        shape=(3,), dtype='long'
 
         """
         return self._D_diag
@@ -617,7 +617,7 @@ def P(self):
         """Left unimodular matrix after SNF: D=PAQ.
 
         Left unimodular matrix after SNF: D=PAQ.
-        shape=(3, 3), dtype='int_', order='C'.
+        shape=(3, 3), dtype='long', order='C'.
 
         """
         return self._P
@@ -627,7 +627,7 @@ def Q(self):
         """Right unimodular matrix after SNF: D=PAQ.
 
         Right unimodular matrix after SNF: D=PAQ.
-        shape=(3, 3), dtype='int_', order='C'.
+        shape=(3, 3), dtype='long', order='C'.
 
         """
         return self._Q
@@ -694,7 +694,7 @@ def _set_mesh_numbers(
                 coordinates,
             )
         if num_values == 3:
-            self._D_diag = np.array(mesh, dtype="int_")
+            self._D_diag = np.array(mesh, dtype="long")
 
     def _run_grg(
         self,
@@ -785,12 +785,12 @@ def _set_GRG_mesh(
                 sym_dataset, length, coordinates=coordinates
             )
         elif grid_matrix is not None:
-            _grid_matrix = np.array(grid_matrix, dtype="int_", order="C")
+            _grid_matrix = np.array(grid_matrix, dtype="long", order="C")
 
         # If grid_matrix is a diagonal matrix, use it as D matrix.
         gm_diag = np.diagonal(_grid_matrix)
         if (np.diag(gm_diag) == _grid_matrix).all() and not force_SNF:
-            self._D_diag = np.array(gm_diag, dtype="int_")
+            self._D_diag = np.array(gm_diag, dtype="long")
         else:
             import phono3py._recgrid as recgrid
 
@@ -849,7 +849,7 @@ def _get_grid_matrix(
         inv_tmat_int = np.rint(inv_tmat).astype(int)
         assert (np.abs(inv_tmat - inv_tmat_int) < 1e-5).all()
         grid_matrix = np.array(
-            (inv_tmat_int * conv_mesh_numbers).T, dtype="int_", order="C"
+            (inv_tmat_int * conv_mesh_numbers).T, dtype="long", order="C"
         )
         return grid_matrix
 
@@ -875,12 +875,12 @@ def get_grid_point_from_address(address, D_diag):
     ----------
     address : array_like
         Grid address.
-        shape=(3, ) or (n, 3), dtype='int_'
+        shape=(3, ) or (n, 3), dtype='long'
     D_diag : array_like
         This corresponds to mesh numbers. More precisely, this gives
         diagonal elements of diagonal matrix of Smith normal form of
         grid generating matrix. See the detail in the docstring of BZGrid.
-        shape=(3,), dtype='int_'
+        shape=(3,), dtype='long'
 
     Returns
     -------
@@ -890,18 +890,18 @@ def get_grid_point_from_address(address, D_diag):
 
     ndarray
         GR-grid point indices.
-        shape=(n, ), dtype='int_'
+        shape=(n, ), dtype='long'
 
     """
     import phono3py._recgrid as recgrid
 
-    adrs_array = np.array(address, dtype="int_", order="C")
-    mesh_array = np.array(D_diag, dtype="int_")
+    adrs_array = np.array(address, dtype="long", order="C")
+    mesh_array = np.array(D_diag, dtype="long")
 
     if adrs_array.ndim == 1:
         return recgrid.grid_index_from_address(adrs_array, mesh_array)
 
-    gps = np.zeros(adrs_array.shape[0], dtype="int_")
+    gps = np.zeros(adrs_array.shape[0], dtype="long")
     for i, adrs in enumerate(adrs_array):
         gps[i] = recgrid.grid_index_from_address(adrs, mesh_array)
     return gps
@@ -917,15 +917,15 @@ def get_ir_grid_points(bz_grid: BZGrid):
     -------
     ir_grid_points : ndarray
         Irreducible grid point indices in GR-grid.
-        shape=(num_ir_grid_points, ), dtype='int_'
+        shape=(num_ir_grid_points, ), dtype='long'
     ir_grid_weights : ndarray
         Weights of irreducible grid points. Its sum is the number of
         grid points in GR-grid (prod(D_diag)).
-        shape=(num_ir_grid_points, ), dtype='int_'
+        shape=(num_ir_grid_points, ), dtype='long'
     ir_grid_map : ndarray
         Index mapping table to irreducible grid points from all grid points
         such as, [0, 0, 2, 3, 3, ...].
-        shape=(prod(D_diag), ), dtype='int_'
+        shape=(prod(D_diag), ), dtype='long'
 
     """
     ir_grid_map = _get_ir_grid_map(bz_grid.D_diag, bz_grid.rotations, PS=bz_grid.PS)
@@ -949,7 +949,7 @@ def get_grid_points_by_rotations(
         Rotation matrices {R} with respect to basis vectors of GR-grid.
         Defined by g'=Rg, where g is the grid point address represented by
         three integers in BZ-grid.
-        dtype='int_', shape=(rotations, 3, 3)
+        dtype='long', shape=(rotations, 3, 3)
     with_surface : Bool, optional
         This parameter affects to how to treat grid points on BZ surface.
         When False, rotated BZ surface points are moved to representative
@@ -961,7 +961,7 @@ def get_grid_points_by_rotations(
     -------
     rot_grid_indices : ndarray
         BZ-grid point indices obtained after rotating a grid point index.
-        dtype='int_', shape=(rotations,)
+        dtype='long', shape=(rotations,)
 
     """
     if reciprocal_rotations is not None:
@@ -993,7 +993,7 @@ def _get_grid_points_by_bz_rotations(bz_gp, bz_grid: BZGrid, rotations, lang="C"
 def _get_grid_points_by_bz_rotations_c(bz_gp, bz_grid: BZGrid, rotations):
     import phono3py._recgrid as recgrid
 
-    bzgps = np.zeros(len(rotations), dtype="int_")
+    bzgps = np.zeros(len(rotations), dtype="long")
     for i, r in enumerate(rotations):
         bzgps[i] = recgrid.rotate_bz_grid_index(
             bz_gp,
@@ -1017,7 +1017,7 @@ def _get_grid_points_by_bz_rotations_py(bz_gp, bz_grid: BZGrid, rotations):
     """
     rot_adrs = np.dot(rotations, bz_grid.addresses[bz_gp])
     grgps = get_grid_point_from_address(rot_adrs, bz_grid.D_diag)
-    bzgps = np.zeros(len(grgps), dtype="int_")
+    bzgps = np.zeros(len(grgps), dtype="long")
     if bz_grid.store_dense_gp_map:
         for i, (gp, adrs) in enumerate(zip(grgps, rot_adrs)):
             indices = np.where(
@@ -1057,20 +1057,20 @@ def _get_grid_address(D_diag):
     ----------
     D_diag : array_like
         Three integers that represent the generalized regular grid.
-        shape=(3, ), dtype='int_'
+        shape=(3, ), dtype='long'
 
     Returns
     -------
     gr_grid_addresses : ndarray
         Integer triplets that represents grid point addresses in
         generalized regular grid.
-        shape=(prod(D_diag), 3), dtype='int_'
+        shape=(prod(D_diag), 3), dtype='long'
 
     """
     import phono3py._recgrid as recgrid
 
-    gr_grid_addresses = np.zeros((np.prod(D_diag), 3), dtype="int_")
-    recgrid.gr_grid_addresses(gr_grid_addresses, np.array(D_diag, dtype="int_"))
+    gr_grid_addresses = np.zeros((np.prod(D_diag), 3), dtype="long")
+    recgrid.gr_grid_addresses(gr_grid_addresses, np.array(D_diag, dtype="long"))
     return gr_grid_addresses
 
 
@@ -1139,37 +1139,37 @@ def _relocate_BZ_grid_address(
     import phono3py._recgrid as recgrid
 
     if PS is None:
-        _PS = np.zeros(3, dtype="int_")
+        _PS = np.zeros(3, dtype="long")
     else:
-        _PS = np.array(PS, dtype="int_")
-    bz_grid_addresses = np.zeros((np.prod(D_diag) * 8, 3), dtype="int_", order="C")
-    bzg2grg = np.zeros(len(bz_grid_addresses), dtype="int_")
+        _PS = np.array(PS, dtype="long")
+    bz_grid_addresses = np.zeros((np.prod(D_diag) * 8, 3), dtype="long", order="C")
+    bzg2grg = np.zeros(len(bz_grid_addresses), dtype="long")
 
     if store_dense_gp_map:
-        bz_map = np.zeros(np.prod(D_diag) + 1, dtype="int_")
+        bz_map = np.zeros(np.prod(D_diag) + 1, dtype="long")
     else:
-        bz_map = np.zeros(np.prod(D_diag) * 9 + 1, dtype="int_")
+        bz_map = np.zeros(np.prod(D_diag) * 9 + 1, dtype="long")
 
     # Mpr^-1 = Lr^-1 Lp
     reclat_T = np.array(np.transpose(reciprocal_lattice), dtype="double", order="C")
     reduced_basis = get_reduced_bases(reclat_T)
     tmat_inv = np.dot(np.linalg.inv(reduced_basis.T), reclat_T.T)
-    tmat_inv_int = np.rint(tmat_inv).astype("int_")
+    tmat_inv_int = np.rint(tmat_inv).astype("long")
     assert (np.abs(tmat_inv - tmat_inv_int) < 1e-5).all()
 
     num_gp = recgrid.bz_grid_addresses(
         bz_grid_addresses,
         bz_map,
         bzg2grg,
-        np.array(D_diag, dtype="int_"),
-        np.array(np.dot(tmat_inv_int, Q), dtype="int_", order="C"),
+        np.array(D_diag, dtype="long"),
+        np.array(np.dot(tmat_inv_int, Q), dtype="long", order="C"),
         _PS,
         np.array(reduced_basis.T, dtype="double", order="C"),
         store_dense_gp_map * 1 + 1,
     )
 
-    bz_grid_addresses = np.array(bz_grid_addresses[:num_gp], dtype="int_", order="C")
-    bzg2grg = np.array(bzg2grg[:num_gp], dtype="int_")
+    bz_grid_addresses = np.array(bz_grid_addresses[:num_gp], dtype="long", order="C")
+    bzg2grg = np.array(bzg2grg[:num_gp], dtype="long")
     return bz_grid_addresses, bz_map, bzg2grg
 
 
@@ -1182,34 +1182,34 @@ def _get_ir_grid_map(D_diag, grg_rotations, PS=None):
         This corresponds to mesh numbers. More precisely, this gives
         diagonal elements of diagonal matrix of Smith normal form of
         grid generating matrix. See the detail in the docstring of BZGrid.
-        shape=(3,), dtype='int_'
+        shape=(3,), dtype='long'
     grg_rotations : array_like
         GR-grid rotation matrices.
-        dtype='int_', shape=(grg_rotations, 3)
+        dtype='long', shape=(grg_rotations, 3)
     PS : array_like
         GR-grid shift defined.
-        dtype='int_', shape=(3,)
+        dtype='long', shape=(3,)
 
     Returns
     -------
     ir_grid_map : ndarray
         Grid point mapping from all indices to ir-gird-point indices in GR-grid.
-        dtype='int_', shape=(prod(mesh),)
+        dtype='long', shape=(prod(mesh),)
 
     """
     import phono3py._recgrid as recgrid
 
-    ir_grid_map = np.zeros(np.prod(D_diag), dtype="int_")
+    ir_grid_map = np.zeros(np.prod(D_diag), dtype="long")
     if PS is None:
-        _PS = np.zeros(3, dtype="int_")
+        _PS = np.zeros(3, dtype="long")
     else:
-        _PS = np.array(PS, dtype="int_")
+        _PS = np.array(PS, dtype="long")
 
     num_ir = recgrid.ir_grid_map(
         ir_grid_map,
-        np.array(D_diag, dtype="int_"),
+        np.array(D_diag, dtype="long"),
         _PS,
-        np.array(grg_rotations, dtype="int_", order="C"),
+        np.array(grg_rotations, dtype="long", order="C"),
     )
 
     if num_ir > 0:
diff --git a/phono3py/phonon/solver.py b/phono3py/phonon/solver.py
index 6c216a49..9136e0ba 100644
--- a/phono3py/phonon/solver.py
+++ b/phono3py/phonon/solver.py
@@ -67,7 +67,7 @@ def run_phonon_solver_c(
         See Interaction.get_phonons().
     grid_points : ndarray
         Grid point indices.
-        shape=(grid_points, ), dtype='int_'
+        shape=(grid_points, ), dtype='long'
     grid_address : ndarray
         See BZGrid.addresses.
     QDinv : ndarray
@@ -127,7 +127,7 @@ def run_phonon_solver_c(
         is_nac_q_zero = True
         _nac_q_direction = np.array(nac_q_direction, dtype="double")
 
-    assert grid_points.dtype == np.dtype("int_")
+    assert grid_points.dtype == np.dtype("long")
     assert grid_points.flags.c_contiguous
     assert QDinv.dtype == np.dtype("double")
     assert QDinv.flags.c_contiguous
@@ -256,4 +256,4 @@ def _get_fc_elements_mapping(dm, fc):
         fc_p2s = np.arange(len(p2s_map), dtype="intc")
         fc_s2p = s2pp_map
 
-    return np.array(fc_p2s, dtype="int_"), np.array(fc_s2p, dtype="int_")
+    return np.array(fc_p2s, dtype="long"), np.array(fc_s2p, dtype="long")
diff --git a/phono3py/phonon3/collision_matrix.py b/phono3py/phonon3/collision_matrix.py
index a7fd3764..f56a3135 100644
--- a/phono3py/phonon3/collision_matrix.py
+++ b/phono3py/phonon3/collision_matrix.py
@@ -91,7 +91,7 @@ def __init__(
         if not self._is_reducible_collision_matrix:
             self._num_ir_grid_points = num_ir_grid_points
             self._rot_grid_points = np.array(
-                self._pp.bz_grid.bzg2grg[rot_grid_points], dtype="int_", order="C"
+                self._pp.bz_grid.bzg2grg[rot_grid_points], dtype="long", order="C"
             )
             self._rotations_cartesian = rotations_cartesian
 
@@ -269,8 +269,8 @@ def _get_gp2tp_map(self):
         """
         map_triplets = self._triplets_map_at_q
         map_q = self._ir_map_at_q
-        gp2tp = -np.ones(len(map_triplets), dtype="int_")
-        tp2s = -np.ones(len(map_triplets), dtype="int_")
+        gp2tp = -np.ones(len(map_triplets), dtype="long")
+        tp2s = -np.ones(len(map_triplets), dtype="long")
         swapped = np.zeros(len(map_triplets), dtype="bytes")
         num_tps = 0
 
diff --git a/phono3py/phonon3/fc3.py b/phono3py/phonon3/fc3.py
index 817a06ff..9f8d0521 100644
--- a/phono3py/phonon3/fc3.py
+++ b/phono3py/phonon3/fc3.py
@@ -110,13 +110,13 @@ def get_fc3(
     if is_compact_fc and "cutoff_distance" not in disp_dataset:
         s2p_map = primitive.s2p_map
         p2p_map = primitive.p2p_map
-        s2compact = np.array([p2p_map[i] for i in s2p_map], dtype="int_")
+        s2compact = np.array([p2p_map[i] for i in s2p_map], dtype="long")
         target_atoms = [i for i in p2s_map if i not in first_disp_atoms]
     else:
         # distribute_fc3 prefers pure translation operations in distributing
         # fc3. Below, fc3 already computed are distributed to the first index
         # atoms in primitive cell, and then distribute to all the other atoms.
-        s2compact = np.arange(len(supercell), dtype="int_")
+        s2compact = np.arange(len(supercell), dtype="long")
         target_atoms = [i for i in p2s_map if i not in first_disp_atoms]
         distribute_fc3(
             fc3,
@@ -211,7 +211,7 @@ def distribute_fc3(
                     if rot_i in pure_trans_indices:
                         rot_index = rot_i
                         break
-                atom_mapping = np.array(permutations[rot_index], dtype="int_")
+                atom_mapping = np.array(permutations[rot_index], dtype="long")
                 rot = rotations[rot_index]
                 rot_cart_inv = np.array(
                     similarity_transformation(lattice, rot).T, dtype="double", order="C"
@@ -271,10 +271,10 @@ def set_permutation_symmetry_compact_fc3(fc3, primitive):
         s2pp_map, nsym_list = get_nsym_list_and_s2pp(s2p_map, p2p_map, permutations)
         phono3c.permutation_symmetry_compact_fc3(
             fc3,
-            np.array(permutations, dtype="int_", order="C"),
-            np.array(s2pp_map, dtype="int_"),
-            np.array(p2s_map, dtype="int_"),
-            np.array(nsym_list, dtype="int_"),
+            np.array(permutations, dtype="long", order="C"),
+            np.array(s2pp_map, dtype="long"),
+            np.array(p2s_map, dtype="long"),
+            np.array(nsym_list, dtype="long"),
         )
     except ImportError as exc:
         text = (
@@ -325,10 +325,10 @@ def set_translational_invariance_compact_fc3(fc3, primitive: Primitive):
         permutations = primitive.atomic_permutations
         s2pp_map, nsym_list = get_nsym_list_and_s2pp(s2p_map, p2p_map, permutations)
 
-        permutations = np.array(permutations, dtype="int_", order="C")
-        s2pp_map = np.array(s2pp_map, dtype="int_")
-        p2s_map = np.array(p2s_map, dtype="int_")
-        nsym_list = np.array(nsym_list, dtype="int_")
+        permutations = np.array(permutations, dtype="long", order="C")
+        s2pp_map = np.array(s2pp_map, dtype="long")
+        p2s_map = np.array(p2s_map, dtype="long")
+        nsym_list = np.array(nsym_list, dtype="long")
         phono3c.transpose_compact_fc3(
             fc3, permutations, s2pp_map, p2s_map, nsym_list, 0
         )  # dim[0] <--> dim[1]
@@ -492,7 +492,7 @@ def _solve_fc3(
     rot_map_syms = get_positions_sent_by_rot_inv(
         lattice, positions, site_symmetry, symprec
     )
-    rot_map_syms = np.array(rot_map_syms, dtype="int_", order="C")
+    rot_map_syms = np.array(rot_map_syms, dtype="long", order="C")
     rot_disps = get_rotated_displacement(displacements_first, site_sym_cart)
 
     logger.debug("pinv")
@@ -599,10 +599,10 @@ def show_drift_fc3(fc3, primitive=None, name="fc3"):
             p2p_map = primitive.p2p_map
             permutations = primitive.atomic_permutations
             s2pp_map, nsym_list = get_nsym_list_and_s2pp(s2p_map, p2p_map, permutations)
-            permutations = np.array(permutations, dtype="int_", order="C")
-            s2pp_map = np.array(s2pp_map, dtype="int_")
-            p2s_map = np.array(p2s_map, dtype="int_")
-            nsym_list = np.array(nsym_list, dtype="int_")
+            permutations = np.array(permutations, dtype="long", order="C")
+            s2pp_map = np.array(s2pp_map, dtype="long")
+            p2s_map = np.array(p2s_map, dtype="long")
+            nsym_list = np.array(nsym_list, dtype="long")
             num_patom = fc3.shape[0]
             num_satom = fc3.shape[1]
             maxval1 = 0
diff --git a/phono3py/phonon3/interaction.py b/phono3py/phonon3/interaction.py
index 443ad335..c4555bb5 100644
--- a/phono3py/phonon3/interaction.py
+++ b/phono3py/phonon3/interaction.py
@@ -170,8 +170,8 @@ def __init__(
 
         self._svecs, self._multi = self._primitive.get_smallest_vectors()
         self._masses = np.array(self._primitive.masses, dtype="double")
-        self._p2s = np.array(self._primitive.p2s_map, dtype="int_")
-        self._s2p = np.array(self._primitive.s2p_map, dtype="int_")
+        self._p2s = np.array(self._primitive.p2s_map, dtype="long")
+        self._s2p = np.array(self._primitive.s2p_map, dtype="long")
         n_satom, n_patom, _ = self._multi.shape
         self._all_shortest = np.zeros(
             (n_patom, n_satom, n_satom), dtype="byte", order="C"
@@ -233,7 +233,7 @@ def mesh_numbers(self) -> np.ndarray:
         Returns
         -------
         ndarray
-           shape=(3, ), dtype='int_'
+           shape=(3, ), dtype='long'
 
         """
         return self._bz_grid.D_diag
@@ -332,7 +332,7 @@ def band_indices(self) -> np.ndarray:
         Returns
         -------
         ndarray
-            shape=(num_specified_bands, ), dtype='int_'
+            shape=(num_specified_bands, ), dtype='long'
 
         """
         return self._band_indices
@@ -715,7 +715,7 @@ def run_phonon_solver(self, grid_points=None, solve_by_rotation=False):
                 self.run_phonon_solver_with_eigvec_rotation()
             else:
                 self._run_phonon_solver_c(
-                    np.arange(len(self._bz_grid.addresses), dtype="int_")
+                    np.arange(len(self._bz_grid.addresses), dtype="long")
                 )
         else:
             self._run_phonon_solver_c(grid_points)
@@ -743,12 +743,12 @@ def run_phonon_solver_at_gamma(self, is_nac=False):
         self._phonon_done[self._bz_grid.gp_Gamma] = 0
         if is_nac:
             self._done_nac_at_gamma = True
-            self.run_phonon_solver(np.array([self._bz_grid.gp_Gamma], dtype="int_"))
+            self.run_phonon_solver(np.array([self._bz_grid.gp_Gamma], dtype="long"))
         else:
             self._done_nac_at_gamma = False
             _nac_q_direction = self._nac_q_direction
             self._nac_q_direction = None
-            self.run_phonon_solver(np.array([self._bz_grid.gp_Gamma], dtype="int_"))
+            self.run_phonon_solver(np.array([self._bz_grid.gp_Gamma], dtype="long"))
             self._nac_q_direction = _nac_q_direction
 
     def run_phonon_solver_with_eigvec_rotation(self):
@@ -860,7 +860,7 @@ def _get_phonons_at_minus_q(self):
             in this method.
 
         """
-        r_inv = -np.eye(3, dtype="int_")
+        r_inv = -np.eye(3, dtype="long")
         bz_grid_points_solved = []
         for bzgp, done in enumerate(self._phonon_done):
             if done:
@@ -882,7 +882,7 @@ def _get_phonons_at_minus_q(self):
                         [
                             bzgp_mq,
                         ],
-                        dtype="int_",
+                        dtype="long",
                     )
                 )
                 bz_grid_points_solved.append(bzgp_mq)
@@ -925,9 +925,9 @@ def _set_fc3(self, fc3):
     def _set_band_indices(self, band_indices):
         num_band = len(self._primitive) * 3
         if band_indices is None:
-            self._band_indices = np.arange(num_band, dtype="int_")
+            self._band_indices = np.arange(num_band, dtype="long")
         else:
-            self._band_indices = np.array(band_indices, dtype="int_")
+            self._band_indices = np.array(band_indices, dtype="long")
 
     def _run_c(self, g_zero):
         import phono3py._phono3py as phono3c
diff --git a/phono3py/phonon3/joint_dos.py b/phono3py/phonon3/joint_dos.py
index 2bb1add0..8f9e645f 100644
--- a/phono3py/phonon3/joint_dos.py
+++ b/phono3py/phonon3/joint_dos.py
@@ -263,7 +263,7 @@ def set_grid_point(self, grid_point):
                 )
                 raise RuntimeError(msg)
 
-        self.run_phonon_solver(np.array([gamma_gp, grid_point], dtype="int_"))
+        self.run_phonon_solver(np.array([gamma_gp, grid_point], dtype="long"))
 
     def run_phonon_solver(self, grid_points=None):
         """Calculate phonons at grid_points.
@@ -273,7 +273,7 @@ def run_phonon_solver(self, grid_points=None):
 
         """
         if grid_points is None:
-            _grid_points = np.arange(len(self._bz_grid.addresses), dtype="int_")
+            _grid_points = np.arange(len(self._bz_grid.addresses), dtype="long")
         else:
             _grid_points = grid_points
 
@@ -306,11 +306,11 @@ def run_phonon_solver_at_gamma(self, is_nac=False):
         """
         self._phonon_done[self._bz_grid.gp_Gamma] = 0
         if is_nac:
-            self.run_phonon_solver(np.array([self._bz_grid.gp_Gamma], dtype="int_"))
+            self.run_phonon_solver(np.array([self._bz_grid.gp_Gamma], dtype="long"))
         else:
             _nac_q_direction = self._nac_q_direction
             self._nac_q_direction = None
-            self.run_phonon_solver(np.array([self._bz_grid.gp_Gamma], dtype="int_"))
+            self.run_phonon_solver(np.array([self._bz_grid.gp_Gamma], dtype="long"))
             self._nac_q_direction = _nac_q_direction
 
     def run(self):
diff --git a/phono3py/phonon3/triplets.py b/phono3py/phonon3/triplets.py
index aa75bcad..eb93ef54 100644
--- a/phono3py/phonon3/triplets.py
+++ b/phono3py/phonon3/triplets.py
@@ -34,7 +34,8 @@
 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
-from typing import TYPE_CHECKING, Union
+from collections.abc import Sequence
+from typing import TYPE_CHECKING, Optional, Union
 
 import numpy as np
 from phonopy.structure.tetrahedron_method import TetrahedronMethod
@@ -49,11 +50,11 @@
 
 
 def get_triplets_at_q(
-    grid_point,
+    grid_point: int,
     bz_grid: BZGrid,
-    reciprocal_rotations=None,
-    is_time_reversal=True,
-    swappable=True,
+    reciprocal_rotations: Optional[Union[Sequence, np.ndarray]] = None,
+    is_time_reversal: bool = True,
+    swappable: bool = True,
 ):
     """Generate q-point triplets.
 
@@ -66,7 +67,7 @@ def get_triplets_at_q(
     reciprocal_rotations : array_like or None, optional
         Rotation matrices {R} with respect to reciprocal basis vectors.
         Defined by q'=Rq.
-        dtype='int_', shape=(rotations, 3, 3)
+        dtype='long', shape=(rotations, 3, 3)
     is_time_reversal : bool, optional
         Inversion symemtry is added if it doesn't exist. Default is True.
     swappable : bool, optional
@@ -77,10 +78,10 @@ def get_triplets_at_q(
     triplets_at_q : ndarray
         Symmetry reduced number of triplets are stored as grid point
         integer numbers in BZGrid system.
-        shape=(n_triplets, 3), dtype='int_'
+        shape=(n_triplets, 3), dtype='long'
     weights : ndarray
         Weights of triplets in Brillouin zone
-        shape=(n_triplets,), dtype='int_'
+        shape=(n_triplets,), dtype='long'
     map_triplets : ndarray or None
         Mapping table of all triplets to symmetrically independent
         tripelts in generalized regular grid system. More precisely,
@@ -88,11 +89,11 @@ def get_triplets_at_q(
         independent q' of q+q'+q''=G. Considering q' is enough because
         q is fixed and q''=G-q-q' where G is automatically determined
         to choose smallest |G|.
-        shape=(prod(mesh),), dtype='int_'
+        shape=(prod(mesh),), dtype='long'
     map_q : ndarray
         Irreducible q-points stabilized by q-point of specified grid_point
         in generalized regular grid system.
-        shape=(prod(mesh),), dtype='int_'
+        shape=(prod(mesh),), dtype='long'
 
     """
     if reciprocal_rotations is None:
@@ -117,7 +118,7 @@ def get_triplets_at_q(
     return triplets_at_q, weights, map_triplets, map_q
 
 
-def get_all_triplets(grid_point, bz_grid):
+def get_all_triplets(grid_point: int, bz_grid: BZGrid):
     """Return all triplets of a grid point.
 
     Almost equivalent to ``get_nosym_triplets_at_q``.
@@ -125,20 +126,20 @@ def get_all_triplets(grid_point, bz_grid):
 
     """
     triplets_at_q, _ = _get_BZ_triplets_at_q(
-        grid_point, bz_grid, np.arange(np.prod(bz_grid.D_diag), dtype="int_")
+        grid_point, bz_grid, np.arange(np.prod(bz_grid.D_diag), dtype="long")
     )
 
     return triplets_at_q
 
 
-def get_nosym_triplets_at_q(grid_point, bz_grid: BZGrid):
+def get_nosym_triplets_at_q(grid_point: int, bz_grid: BZGrid):
     """Return triplets information without imposing mesh symmetry.
 
     See the docstring of get_triplets_at_q.
 
     """
-    map_triplets = np.arange(np.prod(bz_grid.D_diag), dtype="int_")
-    map_q = np.arange(np.prod(bz_grid.D_diag), dtype="int_")
+    map_triplets = np.arange(np.prod(bz_grid.D_diag), dtype="long")
+    map_q = np.arange(np.prod(bz_grid.D_diag), dtype="long")
     triplets_at_q, weights = _get_BZ_triplets_at_q(grid_point, bz_grid, map_triplets)
 
     return triplets_at_q, weights, map_triplets, map_q
@@ -238,11 +239,11 @@ def _get_triplets_reciprocal_mesh_at_q(
     fixed_grid_number : int
         Grid point of q0
     D_diag : array_like
-        Diagonal part of the diagonal matrix by SNF. shape=(3,), dtype='int_'
+        Diagonal part of the diagonal matrix by SNF. shape=(3,), dtype='long'
     rec_rotations : array_like
         Rotation matrices in reciprocal space, where the rotation matrix R is
         defined like q'=Rq. Time reversal symmetry is taken care of by
-        is_time_reversal. shape=(n_rot, 3, 3), dtype='int_'
+        is_time_reversal. shape=(n_rot, 3, 3), dtype='long'
     is_time_reversal : bool
         Inversion symemtry is added if it doesn't exist.
     swappable : bool
@@ -256,24 +257,24 @@ def _get_triplets_reciprocal_mesh_at_q(
         independent q' of q+q'+q''=G. Considering q' is enough because q is
         fixed and q''=G-q-q' where G is automatically determined to choose
         smallest |G| without considering BZ surface (see docstring of
-        _get_BZ_triplets_at_q.) shape=(prod(mesh),), dtype='int_'
+        _get_BZ_triplets_at_q.) shape=(prod(mesh),), dtype='long'
     map_q : ndarray
         Irreducible q-points stabilized by q-point of specified grid_point.
-        shape=(prod(mesh),), dtype='int_'
+        shape=(prod(mesh),), dtype='long'
 
     """
     import phono3py._phono3py as phono3c
 
-    map_triplets = np.zeros(np.prod(D_diag), dtype="int_")
-    map_q = np.zeros(np.prod(D_diag), dtype="int_")
+    map_triplets = np.zeros(np.prod(D_diag), dtype="long")
+    map_q = np.zeros(np.prod(D_diag), dtype="long")
 
     num_triplets = phono3c.triplets_reciprocal_mesh_at_q(
         map_triplets,
         map_q,
         fixed_grid_number,
-        np.array(D_diag, dtype="int_"),
+        np.array(D_diag, dtype="long"),
         is_time_reversal * 1,
-        np.array(rec_rotations, dtype="int_", order="C"),
+        np.array(rec_rotations, dtype="long", order="C"),
         swappable * 1,
     )
     assert num_triplets == len(np.unique(map_triplets))
@@ -306,40 +307,40 @@ def _get_BZ_triplets_at_q(bz_grid_index, bz_grid: BZGrid, map_triplets):
         q''=G-q-q' where G is automatically determined to choose
         smallest |G| without considering BZ surface (see docstring of
         _get_BZ_triplets_at_q.)
-        shape=(prod(mesh),), dtype='int_'
+        shape=(prod(mesh),), dtype='long'
 
     Returns
     -------
     triplets : ndarray
         Symmetry reduced number of triplets are stored as grid point
         integer numbers.
-        shape=(n_triplets, 3), dtype='int_'
+        shape=(n_triplets, 3), dtype='long'
     ir_weights : ndarray
         Weights of triplets at a fixed q0.
-        shape=(n_triplets,), dtype='int_'
+        shape=(n_triplets,), dtype='long'
 
     """
     import phono3py._phono3py as phono3c
 
-    weights = np.zeros(len(map_triplets), dtype="int_")
+    weights = np.zeros(len(map_triplets), dtype="long")
     for g in map_triplets:
         weights[g] += 1
     ir_weights = np.extract(weights > 0, weights)
-    triplets = -np.ones((len(ir_weights), 3), dtype="int_")
+    triplets = -np.ones((len(ir_weights), 3), dtype="long")
     num_ir_ret = phono3c.BZ_triplets_at_q(
         triplets,
         bz_grid_index,
         bz_grid.addresses,
         bz_grid.gp_map,
         map_triplets,
-        np.array(bz_grid.D_diag, dtype="int_"),
+        np.array(bz_grid.D_diag, dtype="long"),
         bz_grid.Q,
         bz_grid.store_dense_gp_map * 1 + 1,
     )
 
     assert num_ir_ret == len(ir_weights)
 
-    return triplets, np.array(ir_weights, dtype="int_")
+    return triplets, np.array(ir_weights, dtype="long")
 
 
 def _set_triplets_integration_weights_c(
@@ -357,7 +358,7 @@ def _set_triplets_integration_weights_c(
         g,
         g_zero,
         frequency_points,  # f0
-        np.array(np.dot(tetrahedra, pp.bz_grid.P.T), dtype="int_", order="C"),
+        np.array(np.dot(tetrahedra, pp.bz_grid.P.T), dtype="long", order="C"),
         pp.bz_grid.D_diag,
         triplets_at_q,
         frequencies,  # f1
@@ -380,7 +381,7 @@ def _set_triplets_integration_weights_py(
     thm = TetrahedronMethod(pp.bz_grid.microzone_lattice)
     triplets_at_q = pp.get_triplets_at_q()[0]
     tetrahedra_vertices = _get_tetrahedra_vertices(
-        np.array(np.dot(thm.tetrahedra, pp.bz_grid.P.T), dtype="int_", order="C"),
+        np.array(np.dot(thm.tetrahedra, pp.bz_grid.P.T), dtype="long", order="C"),
         triplets_at_q,
         pp.bz_grid,
     )
@@ -414,7 +415,7 @@ def _get_tetrahedra_vertices(relative_address, triplets_at_q, bz_grid: BZGrid):
 
     """
     num_triplets = len(triplets_at_q)
-    vertices = np.zeros((num_triplets, 2, 24, 4), dtype="int_")
+    vertices = np.zeros((num_triplets, 2, 24, 4), dtype="long")
     for i, tp in enumerate(triplets_at_q):
         for j, adrs_shift in enumerate((relative_address, -relative_address)):
             adrs = bz_grid.addresses[tp[j + 1]] + adrs_shift
diff --git a/test/phonon/test_grid.py b/test/phonon/test_grid.py
index a43646f0..6f094caa 100644
--- a/test/phonon/test_grid.py
+++ b/test/phonon/test_grid.py
@@ -1446,7 +1446,7 @@ def test_agno2_BZGrid_with_shift(agno2_cell: PhonopyAtoms):
 def test_relocate_BZ_grid_address_FCC():
     """Test of _relocate_BZ_grid_address by FCC."""
     D_diag = [4, 4, 4]
-    Q = np.eye(3, dtype="int_")
+    Q = np.eye(3, dtype="long")
     reciprocal_lattice = np.array([[-1, 1, 1], [1, -1, 1], [1, 1, -1]], dtype="double")
     bz_grid_addresses, bz_map, bzg2grg = _relocate_BZ_grid_address(
         D_diag,

From 2718cec5317423a687dce3282848cb93db8dfda9 Mon Sep 17 00:00:00 2001
From: Atsushi Togo <atz.togo@gmail.com>
Date: Mon, 23 Dec 2024 13:07:21 +0900
Subject: [PATCH 3/3] Set version 3.10.1

---
 doc/changelog.md    | 4 ++++
 doc/conf.py         | 2 +-
 phono3py/version.py | 2 +-
 3 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/doc/changelog.md b/doc/changelog.md
index 404499f6..85cc3446 100644
--- a/doc/changelog.md
+++ b/doc/changelog.md
@@ -2,6 +2,10 @@
 
 # Change Log
 
+## Dec-23-2024: Version 3.10.1
+
+- Replace `dtype="int_"` by `dtype="long"`.
+
 ## Dec-6-2024: Version 3.10.0
 
 - Update to follow the change of phonopy's internal functions
diff --git a/doc/conf.py b/doc/conf.py
index 4f382595..319c91eb 100644
--- a/doc/conf.py
+++ b/doc/conf.py
@@ -60,7 +60,7 @@
 # The short X.Y version.
 version = "3.10"
 # The full version, including alpha/beta/rc tags.
-release = "3.10.0"
+release = "3.10.1"
 
 # The language for content autogenerated by Sphinx. Refer to documentation
 # for a list of supported languages.
diff --git a/phono3py/version.py b/phono3py/version.py
index 96450c2b..97046b22 100644
--- a/phono3py/version.py
+++ b/phono3py/version.py
@@ -34,4 +34,4 @@
 # ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 # POSSIBILITY OF SUCH DAMAGE.
 
-__version__ = "3.10.0"
+__version__ = "3.10.1"