Diffraction corrections to the equilibrium properties of the classical electron gas. Pair correlation function

Abstract

We perform a systematic study of the diffraction corrections (h/≠0) in the high-temperature range (kBT≳1 Ry) for the pair correlation function of the one-component classical electron gas with a neutralizing background, up to the third-order in the plasma parameter Λ=e2/kBTλD. This program is achieved through the effective interaction Vee(r) = (e2/r)(1−e−cr) with c ∼ (thermal De Broglie wavelength)−1, allowing for a straightforward and tractable generalization of the one-component classical plasma model. The nodal expansion of the potential of average force is performed order-by-order with finite Mayer-Salpeter diagrams. The classical results of De Witt (second-order) and Cohen–Murphy (third-order) are recovered in the h/→0 limit. The resummation to all orders of the bubble diagrams gives access to the short-range behavior of the pair correlation function, which is found similar with the Monte-Carlo results.