Multicomponent fluid of hard spheres near a wall

TL;DR

This study compares theoretical and simulation methods for analyzing the density profiles of multicomponent hard-sphere mixtures near a wall, highlighting the strengths and limitations of each approach.

Contribution

It evaluates the performance of density functional theory, rational function approximation, and Monte Carlo simulations for multicomponent hard-sphere mixtures near a wall.

Findings

DFT shows excellent overall performance.

Rational function approximation is reasonably accurate except near the first minimum.

Some unphysical predictions occur with the rational function approximation.

Abstract

The rational function approximation method, density functional theory, and NVT Monte Carlo simulation are used to obtain the density profiles of multicomponent hard-sphere mixtures near a planar hard wall. Binary mixtures with a size ratio 1:3 in which both components occupy a similar volume are specifically examined. The results indicate that the present version of density functional theory yields an excellent overall performance. A reasonably accurate behavior of the rational function approximation method is also observed, except in the vicinity of the first minimum, where it may even predict unphysical negative values.