First-principles electron-electron scattering simulations in warm dense matter*

Obtaining accurate descriptions of the scattering processes in the warm dense matter (WDM) regime will result in better predictions of electrical and thermal conductivities, which are an essential part in the modeling and design of inertial confinement fusion (ICF) experiments. In our approach, we use first-principles calculations to study isochorically heated solid-density beryllium and hydrogen which is closer to plasma conditions, both materials are commonly found in ICF experiments. We go beyond the commonly used Kubo-Greenwood formalism, and instead we utilize the GW approximation to study electron-electron (e-e) scattering through the relationship between the electron self-energy and the e-e scattering rate. We compare e-e scattering rates using two methods: one in which we fit the full-frequency GW self-energies to the Landau theory of the Fermi liquid to approximate energy-dependent lifetimes. Since this model is calculated within the zero-temperature formalism, we model a temperature-dependence by averaging the energy-dependent lifetimes over Fermi occupations and the density of states to obtain an average e-e- scattering rate. The second approach utilizing a low-scaling GW calculation which uses a compressed Matsubara frequency grid to determine state-dependent lifetimes which have an explicit temperature dependence. Our results will lead to the improvement of models used to generate data for simulations of ICF experiments.