Fix bug in alchemically modified bonds
@@ -761,10 +761,10 @@ class AbsoluteAlchemicalFactory(object):
[particle1, particle2, theta0, K] = reference_force.getBondParameters(bond_index)
if bond_index in self.alchemical_bonds:
# Alchemically modified torsion.
- custom_force.addBond(particle1, particle2, particle3, [theta0, K])
+ custom_force.addBond(particle1, particle2, [theta0, K])
else:
# Standard torsion.
- force.addBond(particle1, particle2, particle3, theta0, K)
+ force.addBond(particle1, particle2, theta0, K)
# Add newly-populated forces to system.
system.addForce(force)
