add head selection in lammps

mace/calculators/lammps_mace.py

@@ -8,12 +8,20 @@
 
 @compile_mode("script")
 class LAMMPS_MACE(torch.nn.Module):
-    def __init__(self, model):
+    def __init__(self, model, **kwargs):
         super().__init__()
         self.model = model
         self.register_buffer("atomic_numbers", model.atomic_numbers)
         self.register_buffer("r_max", model.r_max)
         self.register_buffer("num_interactions", model.num_interactions)
+        self.register_buffer(
+            "head",
+            torch.tensor(
+                self.model.heads.index(kwargs.get("head", self.model.heads[0])),
+                dtype=torch.long,
+            ),
+        )
+
         for param in self.model.parameters():
             param.requires_grad = False
 
@@ -27,6 +35,7 @@ def forward(
         compute_displacement = False
         if compute_virials:
             compute_displacement = True
+        data["head"] = self.head
         out = self.model(
             data,
             training=False,

mace/cli/create_lammps_model.py

@@ -4,15 +4,34 @@
 from e3nn.util import jit
 
 from mace.calculators import LAMMPS_MACE
+import argparse
 
 
-def main():
-    assert len(sys.argv) == 2, f"Usage: {sys.argv[0]} model_path"
+def parse_args():
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--model_path",
+        type=str,
+        required=True,
+        help="Path to the model to be converted to LAMMPS",
+    )
+    parser.add_argument(
+        "--head",
+        type=str,
+        nargs="?",
+        help="Head of the model to be converted to LAMMPS",
+        default="default",
+    )
+    return parser.parse_args()
+
 
-    model_path = sys.argv[1]  # takes model name as command-line input
+def main():
+    args = parse_args()
+    model_path = args.model_path  # takes model name as command-line input
+    head = args.head
     model = torch.load(model_path)
     model = model.double().to("cpu")
-    lammps_model = LAMMPS_MACE(model)
+    lammps_model = LAMMPS_MACE(model, head=head)
     lammps_model_compiled = jit.compile(lammps_model)
     lammps_model_compiled.save(model_path + "-lammps.pt")