diff --git a/emmet-core/emmet/core/charge_density.py b/emmet-core/emmet/core/charge_density.py
index c7ecf8645b..9dc97d017c 100644
--- a/emmet-core/emmet/core/charge_density.py
+++ b/emmet-core/emmet/core/charge_density.py
@@ -1,7 +1,5 @@
 from pydantic import BaseModel, Field
 from datetime import datetime
-from pymatgen.io.vasp import Chgcar
-from maggma.api.models import S3URLDoc
 
 
 class ChgcarDataDoc(BaseModel):
@@ -9,10 +7,13 @@ class ChgcarDataDoc(BaseModel):
     Electron charge density metadata for selected materials.
     """
 
-    fs_id: str = Field(None, description="Unique object ID for the charge density data.")
+    fs_id: str = Field(
+        None, description="Unique object ID for the charge density data."
+    )
 
     last_updated: datetime = Field(
-        None, description="Timestamp for the most recent update to the charge density data.",
+        None,
+        description="Timestamp for the most recent update to the charge density data.",
     )
 
     task_id: str = Field(
diff --git a/emmet-core/setup.py b/emmet-core/setup.py
index 80a4c46590..0e99ceae6b 100644
--- a/emmet-core/setup.py
+++ b/emmet-core/setup.py
@@ -32,6 +32,7 @@
         "pydantic==1.8.2",
         "pybtex~=0.24",
         "typing-extensions>=3.7,<5.0",
+        "spglib<2.0.0",
     ],
     extras_require={
         "all": [