A variational atomic model of plasma accounting for ion radial correlations and electronic structure of ions (VAMPIRES)

TL;DR

This paper introduces VAMPIRES, a model for ion-electron plasma that incorporates ion-ion correlations and electronic structure, using a free-energy minimization approach that satisfies the virial theorem.

Contribution

It presents a novel average-atom model for plasma accounting for ion correlations and electronic structure, derived from a free-energy functional minimization.

Findings

Model fulfills the virial theorem

Accounts for ion-ion correlations and electronic structure

Describes plasma with classical nuclei and superposed electronic densities

Abstract

We propose a model of ion-electron plasma (or nucleus-electron plasma) that accounts for the electronic structure around nuclei (i.e. ion structure) as well as for ion-ion correlations. The model equations are obtained through the minimization of an approximate free-energy functional, and it is shown that the model fulfills the virial theorem. The main hypotheses of this model are 1) nuclei are treated as classical indistinguishable particles 2) electronic density is seen as a superposition of a uniform background and spherically-symmetric distributions around each nucleus (system of ions in a plasma) 3) free energy is approached using a cluster expansion (non-overlapping ions) 4) resulting ion fluid is modeled through an approximate integral equation. In the present paper, the model is described only in its average-atom version.