A simple environment-dependent overlap potential and Cauchy violation in solidargon

Abstract

We develop an analytic and environment-dependent interatomic potential for the overlaprepulsion in solid argon, based on an approximate treatment of the non-orthogonaltight-binding theory for closed-shell systems. The present model can reproduce theobserved elastic properties of solid argon well, including the Cauchy violation at highpressures, yet it is very simple. A useful and novel analysis is given to show how the elasticproperties are related to the environment dependence incorporated into a generic pairwisepotential. The present study has a close link to the broad field of computational materialsscience, in which the inclusion of environment dependence in the short-ranged repulsivepart of a potential model is sometimes crucial in predicting the elastic properties correctly.