Direct correlation function of square well fluid with wide well: First order mean spherical approximation

TL;DR

This paper extends the analytical expression for the direct correlation function of square-well fluids within the first-order mean spherical approximation to wider well widths and compares theoretical results with Monte Carlo simulations.

Contribution

It provides an extended analytical expression for wider well widths (2<lambda<3) and validates it against simulation data.

Findings

The extended DCF matches well with Monte Carlo results for lambda=2.1 and 2.5.

Theoretical and simulation results show good agreement for the radial distribution functions.

The work broadens the applicability of the first-order mean spherical approximation to wider well widths.

Abstract

An analytical expression for square-well fluid direct correlation function (DCF) obtained recently by Tang (Y.Tang, J. Chem. Phys. 127, 164504 (2007)) in the first-order mean spherical approximation is extended for wider well widths (2<lambda<3). Theoretically obtained direct correlation functions and radial distribution functions for square-well fluid with lambda=2.1 and lambda=2.5 are compared with corresponding results of Monte-Carlo simulation.