A simple environment-dependent overlap potential and Cauchy violation in solid argon

TL;DR

This paper introduces a simple, environment-dependent interatomic potential for solid argon that accurately reproduces elastic properties and explains Cauchy violation at high pressures, advancing computational materials modeling.

Contribution

It presents a novel, analytic environment-dependent potential based on Tight-Binding theory that captures elastic behavior and Cauchy violation in solid argon.

Findings

Successfully reproduces elastic properties of solid argon

Explains Cauchy violation at high pressures

Highlights importance of environment dependence in potentials

Abstract

We develop an analytic and environment-dependent interatomic potential for the overlap repulsion in solid argon, based on an approximate treatment of the non-orthogonal Tight-Binding theory for the closed-shell systems. The present model can well reproduce the observed elastic properties of solid argon including Cauchy violation at high pressures, yet very simple. A useful and novel analysis is given to show how the elastic properties are related to the environment-dependence incorporated into a generic pairwise potential. The present study has a close link to the broad field of computational materials science, in which the inclusion of environment dependence in short-ranged repulsive part of a potential model is sometimes crucial in predicting the elastic properties correctly.