change learning rate for multihead ft

mace/cli/run_train.py

@@ -160,6 +160,12 @@ def run(args: argparse.Namespace) -> None:
                 args.E0s != "average"
             ), "average atomic energies cannot be used for multiheads finetuning"
             # check that the foundation model has a single head, if not, use the first head
+            args.lr = 0.001
+            args.ema = True
+            args.ema_decay = 0.999
+            logging.info(
+                "Using multiheads finetuning mode, setting learning rate to 0.001 and EMA to True"
+            )
             if hasattr(model_foundation, "heads"):
                 if len(model_foundation.heads) > 1:
                     logging.warning(