Self-consistent treatment of the frequency-independent Breit interaction in Dirac-Fock calculations of atomic structures. II. He- and Be-like ions

Abstract

We systematically study the effect of the inclusion of the frequency-independent Breit interaction - treated perturbatively as well as variationally - on Dirac-Fock total energies and ⟨rk⟩ expectation values for He- and Be-like ions using an algorithm recently described by Reiher and Hinze. Fully numerical, highly accurate solution methods are employed throughout for solving the Dirac-Fock-Coulomb-Breit (DFCB) equations. These methods allow us to investigate the change of the wavefunction upon inclusion of the Breit interaction in the self-consistent field procedure of an atomic structure program.