The symmetry-adapted configurational ensemble approach to the computer simulation of site-disordered solids

TL;DR

This paper introduces a symmetry-adapted configurational ensemble method for simulating site-disordered solids, enabling detailed analysis of local geometries and properties beyond average structures.

Contribution

It presents a novel approach that leverages crystal symmetry to efficiently simulate and analyze disorder in solids using configurational ensembles and statistical mechanics.

Findings

Effective reduction of configurational space using symmetry

Application to various materials demonstrates method's versatility

Provides insights into local structure and properties of disordered solids

Abstract

Site-occupancy disorder, defined as the non-periodic occupation of lattice sites in a crystal structure, is a ubiquitous phenomenon in solid-state physics and chemistry. Examples are mineral solid solutions, synthetic non-stoichiometric compounds and metal alloys. The experimental investigation of these materials using diffraction techniques only provides averaged information of their structure. However, many properties of interest in these solids are determined by the local geometry and degree of disorder, which escape an "average crystal" description, either from experiments or from theory. In this paper, we describe a methodology for the computer simulation of site-disordered solids, based on the consideration of configurational ensembles and statistical mechanics, where the number of occupancy configurations is reduced by taking advantage of the crystal symmetry of the lattice. Thermodynamics and non-thermodynamic properties are then defined from the statistics in the symmetry-adapted configurational ensemble. We will briefly summarize and discuss some recent applications of this methodology to problems in materials science.