ORNSTEIN-ZERNIKE RELATION FOR A FLUID MIXTURE WITH DIRECT CORRELATION FUNCTIONS OF FINITE RANGE

The Ornstein-Zernike relation for an n -component fluid mixture is investigated under the assumption that the direct correlation function between two particles of species i and j, cij(r), is zero when r is greater than Rij ≡(Ri + Rj)/2 (i, j =1,2, …, n). The relation is transformed so as to involve the radial distribution function gij(r) only for r which is smaller than Rij (i, j=1, 2, …, n). The result is applied to a mixture of hard spheres in which Ri, giving the range of the direct correlation functions, is assumed to be the diameter of the hard spheres of species i (i=1, 2, …, n). The direct correlation functions are found in the explicit forms, which are in complete agreement with those obtained by Lebowitz in case of a binary mixture. © 1969, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.