VIRIAL EXPANSION OF A NONADDITIVE HARD-SPHERE MIXTURE

We have computed the fourth virial coefficient of a binary mixture com posed of hard spheres with equal contact diameters for like particles but unequal collision diameter for particles belonging to unlike speci es. The independent irreducible cluster integrals which contribute to the fourth Virial coefficient were evaluated numerically using the Mon te Carlo method. The coexistence line relative to the fluid-fluid phas e transition, calculated through the truncated virial expansion for sm all positive values of the non-additivity parameter, is found to be in good agreement with the Gibbs ensemble Monte Carlo results. (C) 1998 American Institute of Physics. [S0021-9606(98)51121-X].