diff --git a/torchmdnet/datasets/ace.py b/torchmdnet/datasets/ace.py
index 9ab3ecbaf..e2470dcb2 100644
--- a/torchmdnet/datasets/ace.py
+++ b/torchmdnet/datasets/ace.py
@@ -162,7 +162,7 @@ def sample_iter(self, mol_ids=False):
                 mols = list(h5.values())[0].items()
                 load_confs = self._load_confs_2_0
             else:
-                raise RuntimeError(f"Unsuported layout verions: {version}")
+                raise RuntimeError(f"Unsupported layout version: {version}")
 
             # Iterate over the molecules
             for i_mol, (mol_id, mol) in tqdm(
@@ -180,7 +180,7 @@ def sample_iter(self, mol_ids=False):
                 fq = pt.tensor(mol["formal_charges"], dtype=pt.long)
                 q = fq.sum()
 
-                for pos, y, neg_dy, pq, dp in load_confs(mol, n_atoms=len(z)):
+                for i_conf, (pos, y, neg_dy, pq, dp) in enumerate(load_confs(mol, n_atoms=len(z))):
 
                     # Skip samples with large forces
                     if self.max_gradient:
@@ -193,6 +193,7 @@ def sample_iter(self, mol_ids=False):
                     )
                     if mol_ids:
                         args["mol_id"] = mol_id
+                        args["i_conf"] = i_conf
                     data = Data(**args)
 
                     if self.pre_filter is not None and not self.pre_filter(data):