Number-dependence concerns in Gibbs-ensemble Monte Carlo

Abstract

The Gibbs-ensemble Monte Carlo method is a powerful tool for estimating the location of the coexistence curves of model fluids. This note points out, however, some annoying consequences of the fact that in general there may be different numbers of particles in the two phases simulated. If so, the shape of the coexistence curve may be quite unphysical; for example, there will be no critical point. We conclude that it is only with extreme care in this regard that reliable information on critical parameters or the shapes of coexistence curves may be obtained from Gibbs-ensemble computations.