On Calculation of Thermal Conductivity from Einstein Relation in Equilibrium MD

TL;DR

This paper develops a proper definition of integrated heat current in equilibrium molecular dynamics to accurately calculate thermal conductivity under periodic boundary conditions, demonstrating its effectiveness on solid argon and silicon systems.

Contribution

It introduces a new definition of integrated heat current for equilibrium MD, enabling reliable thermal conductivity calculations under periodic boundaries.

Findings

Method accurately computes thermal conductivity for solids.

Results agree with Green-Kubo approach.

Applicable to argon and silicon systems.

Abstract

In equilibrium molecular dynamics, Einstein relation can be used to calculate the thermal conductivity. This method is equivalent to Green-Kubo relation and it does not require a derivation of an analytical form for the heat current. However, it is not commonly used as Green-Kubo relationship. Its wide use is hindered by the lack of a proper definition for integrated heat current (energy moment) under periodic boundary conditions. In this paper, we developed an appropriate definition for integrated heat current to calculate thermal conductivity of solids under periodic conditions. We applied this method to solid argon and silicon based systems; compared and contrasted with the Green-Kubo approach.