Computing Activity Coefficients of Binary Lennard-Jones Mixtures by Gibbs-Duhem Integration

Abstract

We determine activity coefficients of both components of different binary Lennard-Jones mixtures obtained at T * = 2.0 and ρ * = 0.6 by using two different strategies: (i) direct evaluation of the excess chemical potentials of both components applying the potential distribution theorem, and (ii) using the Gibbs-Duhem integration based on the activity coefficients of the counter-component, which was calculated directly from the potential distribution theorem approach. Both methods lead numerically to similar results and therefore offer a route to determine activity coefficients of mixtures with large complex molecules by alternatively calculating chemical potentials of potentially simpler counter-constituents.