Structure of the square-shoulder fluid

TL;DR

This paper presents an analytical approximation method for the structural properties of square-shoulder fluids, offering improved accuracy over traditional Percus-Yevick theory with minimal computational effort.

Contribution

The authors develop a rational function approximation that simplifies the calculation of the radial distribution function and structure factor for square-shoulder fluids, outperforming Percus-Yevick.

Findings

The approximation aligns well with simulation data.

It provides a good balance between accuracy and computational simplicity.

It improves upon Percus-Yevick predictions.

Abstract

The structural properties of square-shoulder fluids are derived from the use of the rational function approximation method. The computation of both the radial distribution function and the static structure factor involves mostly analytical steps, requiring only the numerical solution of a single transcendental equation. The comparison with available simulation data and with numerical solutions of the Percus-Yevick and hypernetted-chain integral equations shows that the present approximation represents an improvement over the Percus-Yevick theory for this system and a reasonable compromise between accuracy and simplicity.