diff --git a/environment.yml b/environment.yml
index 0401680..8ef40d9 100644
--- a/environment.yml
+++ b/environment.yml
@@ -19,5 +19,6 @@ dependencies:
   - mp-api
   - sqlalchemy
   - aimsgb
+  - pymatgen
   - pip:
     - "git+https://github.com/RDFLib/rdflib-sqlalchemy.git@develop"
diff --git a/setup.py b/setup.py
index a21d9a7..8a5b520 100644
--- a/setup.py
+++ b/setup.py
@@ -19,7 +19,7 @@
     install_requires=['numpy', 'ase', 'rdflib', 
     'pyyaml', 'graphviz', 'networkx', 
     'pyscal3', 'spglib', 'pandas', 'owlready2',
-    'atomman', 'mp-api', 'aimsgb'],
+    'atomman', 'mp-api', 'aimsgb', 'pymatgen'],
     classifiers=[
         'Programming Language :: Python :: 3'
     ],