RELATIVISTIC MANY-BODY PERTURBATION CALCULATIONS FOR OPEN-SHELL SYSTEMS

Relativistic correlation energies have been computed for the open-shel l ground states of group I B and III A elements up to Z = 79 (B, Al, G a, In, Cu, Ag, Au), as well as their singly ionized closed-shell ions, by means of a recently developed relativistic many-body perturbation theory for open-shell multiplet states. All electrons are included in the correlation calculations. Analytic basis sets of Gaussian spinors are employed to expand the upper and lower components of the Dirac fou r-spinors in open-shell matrix Dirac-Fock and relativistic many-body p erturbation procedures. The state-specific relativistic many-body pert urbation theory for open-shell multiplet states involves a full implem entation of generalized Moller-Plesset perturbation theory and account s for both relativistic and electron correlation effects. The ionizati on energies have been calculated for the atoms, and the effects of rel ativity, electron correlation, and the nonadditive interplay of these effects on the ionization energies are analyzed.