QEHeat: An open-source energy flux calculator for the computation of heat-transport coefficients from first principles

TL;DR

QEHeat is an open-source tool that calculates heat-transport coefficients from first principles using density-functional theory and Green-Kubo linear response, aiding in the study of thermal properties of materials.

Contribution

It introduces a new expression for adiabatic energy flux derived from density-functional theory, implemented in an open-source QE module for computing heat conductivity from equilibrium molecular dynamics.

Findings

Provides a practical method for estimating heat conductivity from ab initio simulations.

Implementation in QE makes the method accessible to the materials modeling community.

Facilitates accurate thermal property calculations from first principles.

Abstract

We give a detailed presentation of the theory and numerical implementation of an expression for the adiabatic energy flux in extended systems, derived from density-functional theory. This expression can be used to estimate the heat conductivity from equilibrium ab initio molecular dynamics, using the Green-Kubo linear response theory of transport coefficients. Our expression is implemented in an open-source component of the QE suite of computer codes for quantum mechanical materials modelling, which is being made publicly available.