A multi-objective optimization procedure to develop modified-embedded-atom-method potentials: an application to magnesium

TL;DR

This paper introduces a multi-objective optimization method to develop a new MEAM potential for magnesium, achieving better agreement with experimental and DFT data than previous potentials.

Contribution

A novel multi-objective optimization procedure for creating MEAM potentials with minimal manual fitting, demonstrated on magnesium.

Findings

New MEAM potential for Mg shows improved accuracy.

Potential reproduces elastic, surface, and vacancy properties well.

Outperforms previous potentials in agreement with experiments and DFT.

Abstract

We have developed a multi-objective optimization (MOO) procedure to construct modified-embedded-atom-method (MEAM) potentials with minimal manual fitting. This procedure has been applied successfully to develop a new MEAM potential for magnesium. The MOO procedure is designed to optimally reproduce multiple target values that consist of important materials properties obtained from experiments and first-principles calculations based on density-functional theory (DFT). The optimized target quantities include elastic constants, cohesive energies, surface energies, vacancy formation energies, and the forces on atoms in a variety of structures. The accuracy of the new potential is assessed by computing several material properties of Mg and comparing them with those obtained from other potentials previously published. We found that the present MEAM potential yields a significantly better overall agreement with DFT calculations and experiments.