Some expectation values for Be-like ions derived from pair-correlated wave functions

Abstract

Pair-correlated energies are reported for the ground states of a series of Be-like ions and, in particular, an assessment is made of the influence which individual pair correlations alone have on various one-particle expectation properties. The small changes which occur were, generally, heavily dominated by the $L$-shell effect, which became more pronounced as $Z$ became larger.