diff --git a/jitterbug/model/soap.py b/jitterbug/model/soap.py
index fdf76ac..e0bdda4 100644
--- a/jitterbug/model/soap.py
+++ b/jitterbug/model/soap.py
@@ -161,7 +161,7 @@ def calculate(self, atoms=None, properties=('energy', 'forces', 'energies'),
             grad_outputs=torch.ones_like(pred_energy),
         )[0]  # Derivative of the energy with respect to the descriptors for each center
         d_energy_d_center_d_pos = torch.einsum('ijkl,il->ijk', d_desc_d_pos, d_energy_d_desc)  # Derivative for each center with respect to each atom
-        pred_forces = -d_energy_d_center_d_pos.sum(dim=0) * scale # Total effect on each center from each atom
+        pred_forces = -d_energy_d_center_d_pos.sum(dim=0) * scale  # Total effect on each center from each atom
 
         # Store the results
         self.results['forces'] = pred_forces.detach().numpy()