Thermal Transport by Electrons and Ions in Warm Dense Aluminum: A Combined Density Functional Theory and Deep Potential Study

TL;DR

This paper introduces a combined DFT and deep potential approach to accurately and efficiently evaluate electronic and ionic thermal conductivities in warm dense aluminum across various conditions, addressing convergence and size effects.

Contribution

The study develops a novel integrated method using DFT and deep potentials to systematically analyze thermal conductivities in warm dense matter, improving computational efficiency and accuracy.

Findings

Efficient convergence analysis of electronic thermal conductivity.

Quantitative assessment of ionic thermal conductivity and size effects.

Validation of the combined DFT-DP scheme for warm dense aluminum.

Abstract

We propose an efficient scheme, which combines density functional theory (DFT) with deep potentials (DP), to systematically study the convergence issues of the computed electronic thermal conductivity of warm dense Al (2.7 g/cm$^3$, temperatures ranging from 0.5 to 5.0 eV) with respect to the number of $k$-points, the number of atoms, the broadening parameter, the exchange-correlation functionals and the pseudopotentials. Furthermore, the ionic thermal conductivity is obtained by the Green-Kubo method in conjunction with DP molecular dynamics simulations, and we study the size effects in affecting the ionic thermal conductivity. This work demonstrates that the proposed method is efficient in evaluating both electronic and ionic thermal conductivities of materials.