Thermalized and mixed meanfield ADP potentials for magnesium hydrides

TL;DR

This paper introduces a new meanfield approximation and numerical methods for angular-dependent interatomic potentials in magnesium hydrides, enabling accurate modeling of thermal and compositional effects at finite temperatures.

Contribution

It develops and validates novel thermalized and mixed ADP models for magnesium hydrides, enhancing predictive capabilities for material properties under various conditions.

Findings

TADPs accurately predict thermodynamic properties.

Close agreement between TADPs and Molecular Dynamics results.

Validated models for thermal expansion and elastic constants.

Abstract

We develop meanfield approximation and numerical quadrature schemes for the evaluation of Angular-Dependent interatomic Potentials (ADPs) for magnesium and magnesium hydrides at finite temperature (thermalization) and arbitrary atomic molar fractions (mixing) within a non-equilibrium statistical mechanical framework and derive local equilibrium relations. We numerically verify and experimentally validate the accuracy and fidelity of the resulting thermalized/mixed ADPs (TADPs) by means of selected numerical tests including free entropy, heat capacity, thermal expansion, molar volumes, equation of state and elastic constants. We show that the local equilibrium properties predicted by TADPs agree closely with those computed directly from ADP by means of Molecular Dynamics (MD).