INTEGRAL-EQUATION STUDY OF ADDITIVE 2-COMPONENT MIXTURES OF HARD-SPHERES

The Ornstein-Zernike equation for additive hard sphere mixtures is sol ved numerically by using the Martynov-Sarkisov (MS) closure and a rece nt modification of the Verlet (MV) closure. A comparison of the predic tions for the equation of state and, to a lesser extent, the contact v alues of the radial distribution function, shows both theories to give similar, reasonably accurate, results in most situations. However, an examination of the pair cavity functions for zero separation shows th e two closures to give quite different results, and the MV closure res ults are believed to be better. More attention should be given to the cavity function at zero separation. In addition, the MV closure satisf ies known asymptotic relations for a small concentration of exceedingl y large spheres, whereas the MS and Percus-Yevick closures do not sati sfy these relations.