Multi-Cell Monte Carlo Method for Phase Prediction

TL;DR

The paper introduces a novel Multi-Cell Monte Carlo ((MC)^2) algorithm that predicts stable phases in complex crystalline systems using DFT calculations, effectively handling multi-component systems without existing phase diagrams.

Contribution

It presents the first successful algorithm for simulating phase coexistence in crystalline solids with atomic transfer controlled by the lever rule.

Findings

Successfully predicts stable phases of binary systems.

Applies to complex quaternary high entropy alloys.

Robustly handles systems lacking phase diagrams.

Abstract

We propose a Multi-Cell Monte Carlo algorithm, or (MC)^2, for predicting stable phases in chemically complex crystalline systems. Free atomic transfer among cells is achieved via the application of the lever rule, where an assigned molar ratio virtually controls the percentage of each cell in the overall simulation, making (MC)^2 the first successful algorithm for simulating phase coexistence in crystalline solids. During the application of this method, all energies are computed via direct Density Functional Theory calculations. We test the method by successful prediction of the stable phases of known binary systems. We then apply the method to a quaternary high entropy alloy. The method is particularly robust in predicting stable phases of multi-component systems for which phase diagrams do not exist.