deepcopy atoms.info/structure.properties during ase/pymatgen conversion

this fixes bug where atoms/structure objects were themselves modified when converted

Author: wolearyc

src/pymatgen/io/ase.py

@@ -8,6 +8,7 @@
 import warnings
 from importlib.metadata import PackageNotFoundError
 from typing import TYPE_CHECKING
+import copy
 
 import numpy as np
 from monty.json import MontyDecoder, MSONable, jsanitize
@@ -204,7 +205,7 @@ def get_atoms(structure: SiteCollection, msonable: bool = True, **kwargs) -> MSO
 
         # Atoms.info <---> Structure.properties
         if properties := structure.properties:
-            atoms.info = properties
+            atoms.info = copy.deepcopy(properties)
 
         # Regenerate Spacegroup object from `.todict()` representation
         if isinstance(atoms.info.get("spacegroup"), dict):
@@ -298,10 +299,11 @@ def get_structure(atoms: Atoms, cls: type[Structure] = Structure, **cls_kwargs)
             sel_dyn = None
 
         # Atoms.info <---> Structure.properties
-        # But first make sure `spacegroup` is JSON serializable
-        if atoms.info.get("spacegroup") and isinstance(atoms.info["spacegroup"], Spacegroup):
-            atoms.info["spacegroup"] = atoms.info["spacegroup"].todict()
-        properties = getattr(atoms, "info", {})
+        properties = copy.deepcopy(getattr(atoms, "info", {}))
+        # If present, convert Spacegroup object to JSON-serializable dict
+        if properties.get("spacegroup") and isinstance(properties["spacegroup"], Spacegroup):
+            properties["spacegroup"] = properties["spacegroup"].todict()
+        
 
         # Return a Molecule object if that was specifically requested;
         # otherwise return a Structure object as expected