First Order Expectation Values of Electron Correlation Operators for Two-Electron Atoms

Abstract

Simple analytic first-order wave functions corresponding to two-electron atoms electron correlation operators are obtained by reduction of the Rayleigh-Schrödinger first order perturbation equation to that of one-electron through the partial integration over the variables of one electron. The resulting first order wave functions are applied to evaluate the first order expectation values of electron correlation operators associated with the radial correlation, magnetic shielding and diamagnetic susceptibility. The results obtained have close agreement with other theoretical results.