diff --git a/emle/models/_emle.py b/emle/models/_emle.py
index 7e1c8bb..1a3b4bc 100644
--- a/emle/models/_emle.py
+++ b/emle/models/_emle.py
@@ -408,7 +408,7 @@ def forward(
         charges_mm: Tensor,
         xyz_qm: Tensor,
         xyz_mm: Tensor,
-        qm_charge: Union[int, Tensor] = _torch.tensor(0, dtype=_torch.int64),
+        qm_charge: Union[int, Tensor] = 0,
     ) -> Tensor:
         """
         Computes the static and induced EMLE energy components.
@@ -456,7 +456,7 @@ def forward(
             qm_charge = _torch.full((batch_size,), qm_charge if qm_charge != 0 else self._qm_charge, dtype=_torch.int64, device=self._device)
         elif isinstance(qm_charge, _torch.Tensor):
             if qm_charge.ndim == 0:
-                qm_charge = qm_charge.repeat(batch_size)
+                qm_charge = qm_charge.repeat(batch_size).to(self._device)
 
         # If there are no point charges, return zeros.
         if xyz_mm.shape[1] == 0:
@@ -479,7 +479,7 @@ def forward(
 
         # Compute the static energy.
         if self._method == "mm":
-            q_core = self._q_core_mm
+            q_core = self._q_core_mm.expand(batch_size, -1)
             q_val = _torch.zeros_like(
                 q_core, dtype=self._charges_mm.dtype, device=self._device
             )