Equation of state and correlation functions of strongly coupled plasma mixtures: Density functional theory and analytic models

A recent free-energy model for charged-Yukawa mixtures, based on an extension of the Coulomb ''linear-mixing rule'' to Yukawa charges, enables us to obtain a very accurate equation of state of bulk dense-plasma mixtures. A self-consistent density functional theory for pair correlations predicts the energy to better than a few parts in 10(4) when compared with the best available simulations for both Yukawa and Coulomb plasmas. The simulations results for the tiny deviations from ''linear mixing'' are accurately represented by the hypernetted-chain approximation, as well as by an analytic variational hard-sphere model (which, ironically, both provide only two figures of accuracy for the potential energy). The self-consistent density functional theory provides the most accurate presently available ''first principles'' description for the structure and equation of state of the bulk Coulomb and Yukawa mixtures, and can be applied also to inhomogeneous plasmas.