Correctly handle empty ligand_atoms argumentx
@@ -308,6 +308,10 @@ class AbsoluteAlchemicalFactory(object):
* Can we collect related parameters (e.g. softcore parameters) into a dict?
"""
+ # If no ligand atom set is specified, create an empty list.
+ if ligand_atoms is None:
+ ligand_atoms = list()
+
# Ligand atoms must be list of numpy int type
ligand_atoms = [ int(index) for index in ligand_atoms ]
