Roles of repulsive and attractive forces in determining the structure of nonuniform liquids: generalized mean field theory

TL;DR

This paper develops a generalized mean field theory to understand how repulsive and attractive forces influence the structure of nonuniform liquids, validated by simulations and applicable to Lennard-Jones fluids near a hard wall.

Contribution

It introduces a self-consistent mean field approach that accurately separates and incorporates repulsive and attractive forces in nonuniform liquids.

Findings

Accurate calculation of reference fluid structure using the mean field approach.

Good agreement between theory and Monte Carlo simulations.

Effective separation of force contributions in nonuniform Lennard-Jones liquids.

Abstract

The structure of a nonuniform Lennard-Jones (LJ) liquid near a hard wall is approximated by that of a reference fluid with repulsive intermolecular forces in a self-consistently determined external mean field incorporating the effects of attractive forces. We calculate the reference fluid structure by first determining the response to the slowly varying part of the field alone, followed by the response to the harshly repulsive part. Both steps can be carried out very accurately, as confirmed by MC simulations, and good agreement with the structure of the full LJ fluid is found.