Performance of three mixing rules using different equations of state for hard-spheres

The predictions of the pair radial distribution function (RDF) at contact v alue, compressibility factor, and chemical potentials for binary and ternar y hard-sphere mixtures obtained with the Barrio-Solana, the Santos et al., and the generalized Lebowitz mixing rules are compared using the Carnahan-S tarling, Kolafa, and Khoshkbarchi-Vera one-component hard-sphere EOS. An ex pression for the pair RDF at contact value for Barrio-Solana mixing rule an d the expressions for the chemical potentials in multicomponent hard-sphere fluids are derived. As a general rule, the equations of state obtained bas ed on the generalized Lebowitz mixing rule predict better the pair RDF at c ontact value simulated data. The compressibility factor and the chemical po tentials simulation results are generally better predicted by either the Sa ntos et al. or the Barrio-Solana mixing rule, depending on the packing frac tion, the composition, and the diameter ratio values. For a binary hard-sph ere fluid with large diameter ratio, sigma (2)/sigma (1) = 20, in the high- density region and at low mole fractions of the larger component, the Barri o-Solana mixing rule predicts the compressibility factor simulation results considerably more accurately than the other mixing rules studied here. (C) 2001 Elsevier Science B.V. All rights reserved.