Equation of state in the quasi-classical approximation

Abstract

An approximate equation of state is considered that contains a correction for electron-gas inhomogeneity in the exchange-correlation and kinetic energies in the quasi-classical approximation. The problem of finding the model parameters satisfying the condition P=0 has been solved for metals at a normal density. The results of numerical solution of the model equations are presented for degrees of compression. The values of the quasi-classical parameter determining the approximation accuracy are found. The results are illustrated by the dependences on the degree of compression plotted in the range ρ/ρ0=1–106 and by the spatial dependences. Our approach to construction of the equation of state provides for a quite simple but sufficiently accurate approach to the experimental values of the model parameters. Moreover, the proposed model gives much more self-consistent information as compared to conventional approximations. In particular, the ionicity is calculated for an increase in the density. The model equation can also be used instead of the well-known effective bound-electron potential approximation.