add Allegro, OCP and MatterSim to ase_calculator

pyproject.toml

@@ -57,6 +57,7 @@ forcefields = [
     "matgl>=1.1.3",
     "torchdata<=0.7.1",
     # quippy-ase support for py3.12 tracked in https://github.com/libAtoms/QUIP/issues/645
+    "mattersim>=1.0.0rc10.dev1",
     "quippy-ase>=0.9.14; python_version < '3.12'",
     "sevenn>=0.9.3",
     "torchdata<=0.7.1",                            # TODO: remove when issue fixed
@@ -123,6 +124,7 @@ strict-forcefields = [
     "chgnet==0.4.0",
     "mace-torch>=0.3.6",
     "matgl==1.1.3",
+    "mattersim==1.0.0rc10.dev1",
     "quippy-ase==0.9.14; python_version < '3.12'",
     "sevenn==0.10.1",
     "torch==2.5.1",

src/atomate2/forcefields/__init__.py

@@ -20,10 +20,13 @@ class MLFF(Enum):  # TODO inherit from StrEnum when 3.11+
     NEP = "NEP"
     Nequip = "Nequip"
     SevenNet = "SevenNet"
+    Allegro = "Allegro"
+    OCP = "OCP"  # for loading model checkpoint with fairchem.core.OCPCalculator
+    MatterSim = "MatterSim"
 
     @classmethod
     def _missing_(cls, value: Any) -> Any:
-        """Allow input of str(MLFF) as valid enum."""
+        """Allow feeding output of str(MLFF.<model>) back into MLFF(...)."""
         if isinstance(value, str):
             value = value.split("MLFF.")[-1]
         for member in cls:

src/atomate2/forcefields/utils.py

@@ -90,11 +90,28 @@ def ase_calculator(calculator_meta: str | dict, **kwargs: Any) -> Calculator | N
 
             calculator = NequIPCalculator.from_deployed_model(**kwargs)
 
+        elif calculator_name == MLFF.Allegro:
+            from allegro.ase import AllegroCalculator
+
+            calculator = AllegroCalculator.from_deployed_model(**kwargs)
+
         elif calculator_name == MLFF.SevenNet:
             from sevenn.sevennet_calculator import SevenNetCalculator
 
             calculator = SevenNetCalculator(**{"model": "7net-0"} | kwargs)
 
+        elif calculator_name == MLFF.OCP:
+            # this package is not available on PyPI, needs to be installed from source
+            # see https://github.com/FAIR-Chem/fairchem?tab=readme-ov-file#installation
+            from fairchem.core import OCPCalculator
+
+            calculator = OCPCalculator(**kwargs)
+
+        elif calculator_name == MLFF.MatterSim:
+            from mattersim.forcefield import MatterSimCalculator
+
+            calculator = MatterSimCalculator(**kwargs)
+
     elif isinstance(calculator_meta, dict):
         calc_cls = MontyDecoder().process_decoded(calculator_meta)
         calculator = calc_cls(**kwargs)