The relativistic virial theorem in plasma EOS calculations

A method for enhancing EOS calculations is presented. Our model combines the two pressure representations: the basic definition - as the volume derivative of the free energy $F$, and the ``virial pressure'' $P_{v}$ = [$E - c^{2}B$] / 3V derived from the relativistic virial theorem, where $B$ is the lower component contribution to the electronic density. The model takes into account the deviation $\delta $ between the two representations and presents an exact differential equation for $F$ that provides analytic expressions for both $F$ and $P$, in terms of $M=\delta +c^{2}B$ - \textit{TS}. Using the LDA approximation for $M$ in these exact expressions, together with a boundary condition at the normal density, improves the EOS LDA results significantly. We present a survey of comparisons with experiments showing excellent agreements with the calculations.