Fix bug in determining nonbonded lambda variables
@@ -1595,6 +1595,9 @@ class AbsoluteAlchemicalFactory(object):
# Make a list of region names for the alchemical regions interactions which are being built.
lambda_var_suffixes = []
for alchemical_region in alchemical_regions_pairs:
+ if alchemical_region.name is None:
+ lambda_var_suffixes.append('')
+ else:
lambda_var_suffixes.append('_' + alchemical_region.name)
# --------------------------------------------------
