Correlated and Hartree–Fock Wavefunctions for the 1s2s 3S State of Helium

Abstract

Energies are calculated variationally using an antisymmetrized orbital product times the correlation function g = [1 + λr12 + μ(r2 − r1)2]m (m = 12or 1). Energy errors are 0.00013 a.u. when m = 12 and 0.00030 a.u. when m = 1. Values of λ and μ are considerably smaller than in the case of the ground state. The Hartree–Fock energy is found to be − 2.17425 a.u. Various expectation values are reported for all wavefunctions.