Hartree-Fock predictions of the¹P term in the p⁵d configurations of the spectra in the Ar I and Kr I isoelectronic sequences

The 1 P to 3 P separation has been determined by minimizing the energies of the two states explicitly in the Hartree-Fock procedure and then taking the difference of the total energies determined for the two terms. This procedure gives extremely accurate results for K II and Rb II. The accuracy diminishes for more highly ionized atoms, but is still considerably better than that found using the conventional approach. The results of the Hartree-Fock calculations turn out to be qualitatively different for K II and Ca III (Rb II and Sr III). For K II, the 1 P term is calculated to be below the prediction made by the usual approach in all 3p 5 nd configurations. In Ca III this result holds for the 3p 5 3d configuration, while the calculations show the opposite result for all higher configurations. The reasons for this difference are discussed.