CustomNonbondedForce.addInteractionGroup only accepts list (not set)
@@ -885,8 +885,8 @@ class AbsoluteAlchemicalFactory(object):
# Restrict interaction evaluation to be between alchemical atoms and rest of environment.
# TODO: Exclude intra-alchemical region if we are separately handling that through a separate CustomNonbondedForce for decoupling.
- sterics_custom_nonbonded_force.addInteractionGroup(atomset1, atomset2)
- electrostatics_custom_nonbonded_force.addInteractionGroup(atomset1, atomset2)
+ sterics_custom_nonbonded_force.addInteractionGroup(list(atomset1), list(atomset2))
+ electrostatics_custom_nonbonded_force.addInteractionGroup(list(atomset1), list(atomset2))
# Add custom forces.
system.addForce(sterics_custom_nonbonded_force)
