The liquid-vapour coexistence line by computer simulation à la Widom

Abstract

It is shown that the Widom method of evaluating the chemical potential of a fluid [6] which has been exploited recently to obtain liquid entropies and vapour pressures by computer simulation [5] can be used very simply and economically to predict the liquid-vapour coexistence line and the vapour pressure given the form of the potential. The method is illustrated explicitly for liquid chlorine and liquid bromine. It is quite general, is simpler to use than might have been anticipated and provides a powerful test of an assumed form of intermolecular potential.