A Review of Methods for Predicting Fluid Phase Equilibria: Theory and Computer Simulation

This chapter first reviews computer simulation methods for calculating the free energy or chemical potential in a mixture. Particular attention is given to methods suitable for dense gas or liquid mixtures, including umbrella sampling and test particle methods. This is followed by a review of mixture theories based in statistical mechanics. We focus on theories developed since 1967, and include perturbation theory for spherical and nonspherical molecules as well as the fluctuation formulas of Kirkwood and Buff.