for i in range(1, mols.nMolecules()): mol = mols.moleculeAt(i).molecule() mol = mol.edit().rename( MolName("T4P") ) \ .setProperty("charge", charges) \ .setProperty("LJ", ljs) \ .commit() cljff.add(mol) ms = t.elapsed() print("Parameterised all of the water molecules (in %d ms)!" % ms) system = System() system.add(cljff) t.start() nrg = system.energy() ms = t.elapsed() print("System energy = %s - took %d ms" % (nrg, ms)) copy_system = system.__copy__() t.start() nrg = system.energy() ms = t.elapsed() print("System energy = %s - took %d ms" % (nrg, ms))