Non-additive energy effects in molecular liquids

The non-additive contributions to the configurational internal energy of a molecular liquid have been studied. Stogryn's expression for the non-additive, triple dipole energy of non-spherical molecules has been used in a perturbation calculation based on a molecular dynamics simulation of a fluid of diatomic Lennard-Jones molecules. The system studied approximated roughly to chlorine. The total non-additive, three body contribution to the configurational energy was found to be significant, but the effect of the anisotropy of the molecules was relatively small.