diff --git a/src/moffragmentor/sbu/node.py b/src/moffragmentor/sbu/node.py
index a4b6718..ce9e947 100644
--- a/src/moffragmentor/sbu/node.py
+++ b/src/moffragmentor/sbu/node.py
@@ -91,7 +91,7 @@ def _extract_and_wrap(node_indices, all_branching_indices, all_binding_indices,
     branching_to_binding = set(binding_neighbors).intersection(all_branching_indices)
 
     extension_points = []
-    
+
     for branching_idx in branching_to_binding | branching_to_node_metal:
         if branching_idx in node_indices:
             # find extension point
@@ -105,7 +105,7 @@ def _extract_and_wrap(node_indices, all_branching_indices, all_binding_indices,
 
     # Now, make a copy of the structure and replace the indices with dummy atoms
     dummy_structure = Structure.from_sites(mof.structure.sites)
-    print('binding_to_node_metal', binding_to_node_metal)
+    print("binding_to_node_metal", binding_to_node_metal)
     for i in binding_to_node_metal:
         dummy_structure.replace(i, _BINDING_DUMMY)
     for i in branching_to_binding | branching_to_node_metal:
@@ -125,7 +125,7 @@ def _extract_and_wrap(node_indices, all_branching_indices, all_binding_indices,
     )
 
     inverse_mapping = {v[0]: k for k, v in mapping_w_dummy.items()}
-    print('inverse_mapping', inverse_mapping)
+    print("inverse_mapping", inverse_mapping)
     # let's replace here now the atoms with the dummys as doing it beforehand might cause issues
     # (e.g. we do not have the distances for a cutoffdict)
 
@@ -135,7 +135,9 @@ def _extract_and_wrap(node_indices, all_branching_indices, all_binding_indices,
             mol_w_dummy._sites[inverse_mapping[i]] = Site(
                 _BRANCHING_DUMMY,
                 mol_w_dummy._sites[inverse_mapping[i]].coords,
-                properties={"original_species": str(original_mol_w_dummy_species[inverse_mapping[i]])},
+                properties={
+                    "original_species": str(original_mol_w_dummy_species[inverse_mapping[i]])
+                },
             )
 
     for i in binding_to_node_metal: