Coulomb holes and expectation values. II. Configuration interaction wavefunctions

Abstract

The Coulomb hole and several two‐electron expectation values are calculated using a series of configuration interaction (CI) wavefunctions of differing accuracy for heliumlike ions. The behavior of these properties as the basis set is increased is examined. A comparison with the values obtained using explicitly correlated (EC) wavefunctions, see Paper I, allows us to comment upon the relative performance of the CI and EC treatments with regard to two‐electron properties.