Self-consistent and detailed opacities from a non-equilibrium average-atom model

Philos Trans A Math Phys Eng Sci. 2023 Aug 21;381(2253):20220212. doi: 10.1098/rsta.2022.0212. Epub 2023 Jul 3.

Abstract

Modern density functional theory (DFT) is a powerful tool for accurately predicting self-consistent material properties such as equations of state, transport coefficients and opacities in high energy density plasmas, but it is generally restricted to conditions of local thermodynamic equilibrium (LTE) and produces only averaged electronic states instead of detailed configurations. We propose a simple modification to the bound-state occupation factor of a DFT-based average-atom model that captures essential non-LTE effects in plasmas-including autoionization and dielectronic recombination-thus extending DFT-based models to new regimes. We then expand the self-consistent electronic orbitals of the non-LTE DFT-AA model to generate multi-configuration electronic structure and detailed opacity spectra. This article is part of the theme issue 'Dynamic and transient processes in warm dense matter'.

Keywords: average atom; density functional theory; non-LTE; opacity.