# Atomic Bethe-Goldstone calculations of term splittings, ionization potentials, and electron affinities for B, C, N, O, F, and Ne. II. Configurational excitations

## Abstract

Term splittings, ionization potentials, and electron affinities of states in the lowest configurations of atoms with Z from 5 to 10 have been computed. Correlation-energy terms are obtained from variational solution of one- and two-particle Bethe-Goldstone equations, formulated in terms of configurational virtual excitations. This procedure differs from previous calculations (which used orbital virtual excitations) in that LS eigenfunctions are obtained at each stage of the hierarchy of computations. The present procedure makes it possible to compute correlation energies for multideterminantal LS states. Computed results are in reasonable agreement with experiment, but are less satisfactory than results obtained previously with orbital virtual excitations, including three-particle terms. © 1972 The American Physical Society.