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

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 Monte Carlo simulations, and good agreement with the structure of the full LJ fluid is found.