Relativistic Hartree-Fock energies and oscillator strengths for some ions with ns2np ( n=4minus;6) ground-state configuration

Abstract

The lowest s and p levels in the spectra of ions isoelectronic with gallium, indium and thallium Ge(II) through Se(IV), Sn(II) through Te(IV), Pb(II), and Bi(III) are studied using the relativistic single-configuration Hartree-Fock method. The ionization energies, fine structure intervals, sharp series line-strength ratios, and oscillator strengths are computed and compared with experiments. Deviations in line-strength ratios from statistical ratios are discussed. The influence on oscillator strengths of valence- core electron correlations (core polarization) is included within the single-configuration scheme and is investigated. It is found that, for sharp series transitions, core polarization is less important in ions isoelectronic with Ga, In, and Tl than in neutral systems and both core-polarization-corrected and uncorrected oscillator strengths agree with experiments within experimental errors. This good agreement proves that, for sharp series transitions, the relativistic single-configuration Hartree-Fock method yields acceptable results.