ROLES OF REPULSIVE AND ATTRACTIVE FORCES IN DETERMINING THE STRUCTUREOF NONUNIFORM LIQUIDS - GENERALIZED MEAN-FIELD THEORY

The structure of a nonuniform Lennard-Jones (LJ) liquid near a hard wa ll is approximated by that of a reference fluid with repulsive intermo lecular forces in a self-consistently determined external mean field i ncorporating the effects of attractive forces. We calculate the refere nce fluid structure by first determining the response to the slowly va rying part of the field alone, followed by the response to the harshly repulsive part. Both steps can be carried out very accurately, as con firmed by Monte Carlo simulations, and good agreement with the structu re of the full LJ fluid is found.