Mean-field potential calculations of shock-compressed porous carbon

Abstract

The mean-field potential approach with first-principles total energy data as input is used to investigate shock-compressed carbon with initial densities of 3.51, 2.2, 1.85, and $1.6\phantom{\rule{0.3em}{0ex}}\mathrm{g}∕{\mathrm{cm}}^{3}$ up to $1400\phantom{\rule{0.3em}{0ex}}\mathrm{GPa}$. We have calculated the shock Hugoniot, and the temperature and electronic contribution to the heat capacity along the Hugoniot. While excellent agreement with underground nuclear explosion data is obtained, our results do not show the high compressibility of carbon at megabar pressures indicated by recent laser-driven shock wave experiments.