Variational approach to the calculation of the dielectric function of an electron gas: Exchange and collisions

In a recent work of Woo and Jha, the exchange correlations in a uniform electron gas were calculated. They ignored the Coulomb correlations completely. To describe the physical properties of an electron gas at metallic densities, we propose a variational method to calculate the dielectric function which takes into account the local-field corrections due to both Coulomb and exchange holes. © 1971 The American Physical Society.