Numerical study of the role of shielding and exchange effects and of correlation and relativistic corrections in the Dirac-Fock approximation.

Abstract

The purpose of this work is to provide a quantitative underpinning to the qualitative understanding of the various physical effects which play a role in the spectra of many-electron atoms. Shielding and exchange contributions are studied, as functions of the principal quantum number n, the orbital angular momentum l, and the nuclear charge Z, for neutral alkali-metal atoms in the Dirac-Fock (DF) approximation. Fine-structure effects and valence-state correlation corrections to the DF approximation are also considered for these atoms. Breit interaction and correlation corrections are discussed for the core states of noble gases. Previous numerical computations of these various contributions to atomic energy levels by others are extended to provide a larger data set to serve as a basis for the study of estimates and trends.