Three-body interactions in fluids from molecular simulation: Vapor–liquid phase coexistence of argon

Abstract

Gibbs-ensemble molecular simulations are reported for the vapor–liquid phase coexistence of argon using the two-body Lennard-Jones potential. During the simulation, the possible effect of three-body interactions on the pressure and configurational energy of the vapor and liquid phases is estimated by performing calculations with three-body potentials. The intermolecular potentials used for the three-body calculations incorporate the influence of both three-body-dispersion and three-body-repulsion interactions. The results show that three-body repulsion makes a significant contribution to three-body interactions in the liquid phase. The effect of three-body dispersion is offset substantially by three-body repulsion.