Possibility of an unequivocal test of different models of the equation of state of aluminum in the coupling regime Γ∼1-50

The equation of state (EOS) in regimes of density (ρ) and temperature (T) which are inaccessible to experiment has to be determined using theories which may themselves be out of their range of validity. Even for Al, the EOS in the region 0.1<ρ<2 g cm-3, and 1<T<50 eV, where the ionic coupling parameter Γ ranges from 1-∼50, is not unknown. We present results for the EOS using the Thomas-Fermi model (TF), the quotidian equation of state, the Sesame tabulation, and using the density-functional neutral-pseudoatom (NPA) model which is a first-principles theory applicable at strong coupling. It is found that the NPA predictions are very different from the other models, and experiments could provide an unequivocal test of the validity of the different EOS models. We report theoretical results for the Hugoniot, and the electrical conductivity in the regime of interest