Kubo-Greenwood approach to conductivity in dense plasmas with average atom models

TL;DR

This paper introduces an improved Kubo-Greenwood formulation for conductivity in dense plasmas that explicitly includes ionic structure, resulting in better agreement with ab initio results for certain materials.

Contribution

It presents a new formulation of the Kubo-Greenwood approach that incorporates ionic-structure factors and modifies the Ziman-Evans resistivity formula for better accuracy.

Findings

Enhanced agreement with ab initio results for hydrogen and beryllium conductivities.

Modified Ziman-Evans formula effectively accounts for non-free electron states.

Discrepancies remain for aluminum at low temperatures.

Abstract

A new formulation of the Kubo-Greenwood conductivity for average atom models is given. The new formulation improves upon previous by explicitly including the ionic-structure factor. Calculations based on this new expression lead to much improved agreement with ab initio results for DC conductivity of warm dense hydrogen and beryllium, and for thermal conductivity of hydrogen. We also give and test a slightly modified Ziman-Evans formula for the resistivity that includes a non-free electron density of states, thus removing an ambiguity in the original Ziman-Evans formula. Again results based on this expression are in good agreement with ab initio simulations for warm dense beryllium and hydrogen. However, for both these expressions, calculations of the electrical conductivity of warm dense aluminum lead to poor agreement at low temperatures compared to ab initio simulations.