Density functional theory of inhomogeneous fluid mixture based on bridge function

A simple density functional theory is proposed for an inhomogeneous fluid m ixture by approximating its one-particle correlation function in terms of t he second-order direct correlation functions and the bridge function of the corresponding homogeneous system. The theory is applied to predict the str ucture of a binary hard sphere mixture as well as Lennard-Jones fluid mixtu re near a hard wall, and the calculated density profiles for both the compo nents are shown to agree quite well with the corresponding computer simulat ion results for both the systems. This theory for an inhomogeneous fluid mi xture is further applied to homogeneous hard sphere mixture as well as Lenn ard-Jones fluid mixture and the calculated radial distribution functions ar e found to compare quite well with the same obtained through integral equat ion theory of fluid mixture. (C) 2001 American Institute of Physics.