Simple Correlated Wavefunctions for the Ground State of Heliumlike Atoms

Abstract

A number of correlated wavefunctions of simple form were investigated for heliumlike atoms. Instead of the usual Hylleraas expansion the wavefunctions considered contained exponential correlation functions with nonlinear variational parameters. Wavefunctions of this type are usually avoided because of the nonlinear parameters. However, this type of function was chosen to try to determine some simple but relatively good wavefunctions for use in computing atomic properties. Results for atomic numbers 1 through 3 are presented.