diff --git a/mlptrain/config.py b/mlptrain/config.py
index 9ef1d26f..0f8dd597 100644
--- a/mlptrain/config.py
+++ b/mlptrain/config.py
@@ -26,6 +26,13 @@ class _ConfigClass:
         'l_max': 6,  # n_max = 2 l_max
         'sigma_at': 0.5,  # Å
     }
+    # ACE params
+    ace_params = {
+        'N': 4,  # maximum correlation order
+        'r_cut': 4.0,  # outer cutoff of ACE
+        'deg_pair': 5,  # Specify the pair potential
+        'r_cut_pair': 5.0,
+    }
 
     # NeQUIP params
     nequip_params = {'cutoff': 4.0, 'train_fraction': 0.9}
@@ -48,7 +55,7 @@ class _ConfigClass:
         'forces_weight': 5.0,
         'hidden_irreps': '128x0e + 128x1o',
         'batch_size': 10,
-        'r_max': 5,
+        'r_max': 5.0,
         'correlation': 3,
         'device': mace_device,
         'calc_device': 'cpu',
@@ -60,6 +67,7 @@ class _ConfigClass:
         'amsgrad': True,
         'restart_latest': False,
         'save_cpu': True,
+        'dtype': 'float32',
     }
 
     # --------------------- Internal properties ---------------------------
diff --git a/mlptrain/potentials/_base.py b/mlptrain/potentials/_base.py
index 1bab1e5d..6e97fe34 100644
--- a/mlptrain/potentials/_base.py
+++ b/mlptrain/potentials/_base.py
@@ -339,6 +339,7 @@ def copy(self) -> 'MLPotential':
     'Ne': 1,
     'Na': 2,
     'Mg': 1,
+    'S': 3,
     'Cl': 2,
     'Ar': 1,
     'K': 2,
diff --git a/mlptrain/potentials/ace/ace.py b/mlptrain/potentials/ace/ace.py
index 08ecb9a1..25eae4d7 100644
--- a/mlptrain/potentials/ace/ace.py
+++ b/mlptrain/potentials/ace/ace.py
@@ -134,7 +134,8 @@ def _print_input(self, filename: str, **kwargs) -> None:
         _str = ', '.join([f':{s}' for s in self.system.unique_atomic_symbols])
 
         print(
-            f'species = [{_str}]\n' 'N = 4',  # maximum correlation order
+            f'species = [{_str}]\n'
+            f"N = {Config.ace_params['N']}",  # maximum correlation order
             file=inp_file,
         )
 
@@ -173,10 +174,10 @@ def _print_input(self, filename: str, **kwargs) -> None:
         print(
             'r0 = 1.3\n'
             f'r_in = {self._r_in_estimate:.4f}\n'  # inner cutoff of ACE, choose a little more than min dist in dataset
-            'r_cut = 4.0\n'  # outer cutoff of ACE
+            f"r_cut = {Config.ace_params['r_cut']}\n"  # outer cutoff of ACE
             '\n'
-            'deg_pair = 5\n'  # Specify the pair potential
-            'r_cut_pair = 5.0\n',
+            f"deg_pair = {Config.ace_params['deg_pair']}\n"  # Specify the pair potential
+            f"r_cut_pair = {Config.ace_params['r_cut_pair']}\n",
             file=inp_file,
         )