Electrical and Optical Properties of Dense Metal Plasmas and Liquids*

Michael Desjarlais

Pulsed Power Sciences Center, Dept. 1674

Sandia National Laboratories

Accurate computer modeling of electrically or magnetically driven high energy density physics experiments in the vicinity of the metal-insulator transition has, in the past, been hampered by large uncertainties in the electrical properties of the metals common to these experiments, and for many materials of interest this is still the case. A critical regime of interest for many of the pulsed-power driven experiments at Sandia is from moderate compressions over solid density down to one hundred fold expansions from solid, and temperatures from ambient up to several eV. We have begun a program to improve the accuracy of our conductivity and opacity tables and algorithms for these materials. To increase our understanding of this warm dense matter regime, we have performed numerous calculations of the optical conductivity of aluminum, copper, and tungsten using a combination of DFT based molecular dynamics and the Kubo-Greenwood formula. Through a Kramers-Kronig transformation of the real part of the optical conductivity we obtain the absorption coefficient and reflectivity. These calculations explore regimes in which the missing dispersion forces, temperature dependence of the exchange and correlation functionals, and incorrect LDA/GGA band gaps are topics of immediate concern for DFT based studies of warm dense matter.

* Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract No. DE-AC04-94AL85000.