Attraction Between Like-Charged Walls: Short-Ranged Simulations Using Local Molecular Field Theory

TL;DR

This paper investigates the effective attraction between like-charged walls mediated by counterions using local molecular field theory, validated through simulations that agree well with more complex Coulomb system models.

Contribution

The study introduces a simplified LMF simulation approach for charged systems and provides a criterion for its accurate application.

Findings

LMF theory accurately predicts attraction between like-charged walls.

Simulation results agree with complex Coulomb system models.

A criterion for the consistency parameter sigma_min is proposed.

Abstract

Effective attraction between like-charged walls mediated by counterions is studied using local molecular field (LMF) theory. Monte Carlo simulations of the "mimic system'' given by LMF theory, with short-ranged "Coulomb core" interactions in an effective single particle potential incorporating a mean-field average of the long-ranged Coulomb interactions, provide a direct test of the theory, and are in excellent agreement with more complex simulations of the full Coulomb system by Moreira and Netz [Eur. Phys. J. E 8, 33 (2002)]. A simple, generally-applicable criterion to determine the consistency parameter sigma_{min} needed for accurate use of the LMF theory is presented.