Atomic Bethe-Goldstone Calculations of Term Splittings, Ionization Potentials, and Electron Affinities for B, C, N, O, F, and Ne

The ionization potentials, electron affinities, and term splittings of the lowest electronic configurations for first-row atoms for Z from 5 to 10 have been computed. The method used is that applied previously to ground-state correlation energies. Variational calculations equivalent to solution of one- and two-particle Bethe-Goldstone equations are carried out, following approximate Hartree-Fock calculations for each state of each atom or ion considered. Computed quantities are in reasonably good agreement with experiment. Bethe-Goldstone equations as used here are defined in terms of individual orbital excitations. Calculations of three-particle effects are included in some cases, computed with less relative accuracy than the other results. The three-particle terms are not negligible. In particular, they substantially reduce the magnitude of computed electron affinities.