STUDIES IN THE METHOD OF CORRELATED BASIS FUNCTIONS .2. GRAPHICAL ANALYSIS AND INTEGRAL-EQUATION METHODS

Techniques are introduced for accurate evaluation of the combination of overlap and Hamiltonian matrix elements required in a perturbation treatment of the uniform extended Fermi medium by the method of correlated basis functions. The correlated basis consists of Fermi-gas eigenfunctions, each modified by the same state-independent Jastrow correlation factor and normalized to unity. The cluster expansions of the required quantities are given in a diagrammatic representation, and the essential partial summations are performed by means of integral equations. The compound-graphical functions of the Fermi hypernetted-chain theory of the Jastrow ground-state trial function play a central role in the analysis. The structural results obtained are expressed most simply in terms of dressed dynamical correlation bonds and dressed effective potentials. © 1979.