Thermodynamic properties of halogens from a perturbation theory for interaction site model fluids

Abstract

A perturbation theory recently developed for I.S.M. (interaction site model) fluids is used to compute thermodynamic properties of some diatomic fluid models, which can model liquid fluorine, chlorine and bromine. A comparison with data obtained from molecular dynamics shows good agreement in all cases.

The accuracy in pressure and internal energy for the real liquids is of the same order as that of the extended Weeks–Chandler–Andersen theory of Tildesley. Agreement with experiment is also satisfactory for other properties, such as heat capacity at constant volume, expansivity, internal pressure and isothermal compressibility.