On Consistent Definitions of Momentum and Energy Fluxes for Molecular Dynamics Models with Multi-body Interatomic Potentials

TL;DR

This paper introduces a two-level criteria to verify the consistency of continuum quantities like momentum and energy fluxes in molecular dynamics models with multi-body potentials, using specific potentials as examples.

Contribution

It proposes a systematic framework for checking the consistency of continuum definitions in molecular dynamics with multi-body potentials, including derivations and verification methods.

Findings

Derived definitions of tractions and energy fluxes for EAM and Tersoff potentials.

Provided pseudo code for computing these quantities.

Validated the consistency through analytical and numerical verification.

Abstract

In this paper, we propose a two-level criteria to check the consistency of the definitions of continuum quantities in Molecular Dynamics. As examples, we follow the control- volume approach, derive the definitions of the tractions and energy fluxes for EAM potential and Tersoff potential, and provide the pseudo code the computing. Then, we verify the consistency of the definitions by analytical and numerical methods.