A STUDY OF BINARY HARD-CORE YUKAWA MIXTURES BY MOLECULAR-DYNAMICS AND THE MEAN SPHERICAL APPROXIMATION

The static bulk properties of several types of binary mixtures of hard spheres interacting through an attractive Yukawa tail are studied by molecular dynamics (MD) simulation, and the results compared with the predictions of the mean spherical approximation (MSA) using the energy, compressibility, and virial routes. For mixtures with components of equal diameter, our MD results differ significantly, under certain working conditions, from recently reported results of Monte Carlo calculations. For both these mixtures and mixtures with appreciable size mismatch, comparison with the MSA results shows that the "exact" MD data are always more closely approximated by the energy route. These results, which are all consistent with those of a previous study of pure Yukawa fluids, show that, using the energy route, the MSA allows good description of the thermodynamic properties of binary Yukawa mixtures, even in situations departing considerably from ideality.