Thermodynamic Properties of Vapor-Liquid Equilibria from Monte-Carlo Simulation using ab initio Intermolecular Potentials of Systems H2-H2 and F2-F2

Abstract

Abstract In this work, we have been carried out GEMC-NVT simulations in the temperature range 18 K–32 K for fluid hydrogen and in range 60 K–140 K for fluid fluorine using four our developed ab initio 5-site intermolecular potentials for dimers H2-H2 and F2-F2, respectively. The thermodynamic properties of vapor-liquid equilibria and the critical points of fluids hydrogen and fluorine were calculated with the obtained densities of coexisting phases and vapor pressures. The simulation results drived from ab initio pair potentials were compared with those from ab initio potential plus three-body Axilrod-Teller potential and experimental data as well as those from Monte Carlo simulation using Lennard-Jones potentials, Deiters equation of state (D1-EOS) and Benedict-Webb-Rubin equation of state (EOS) reported in the literature.