Transition energies and oscillator strengths of the ${\mathrm{ns}}^2$ ${}_{}{}^1{}_{}{}^{}\mathrm{S}_0^{}{}_{}{}^{}$–nsnp ${}_{}{}^3{}_{}{}^{}\mathrm{P}_1^{}{}_{}{}^{}$${,}^1$${\mathrm{P}}_1$ transitions in Zn i, Rb viii, Hg i, and Rn vii spectra obtained for short basis sets with multiconfigurational Dirac-Fock ‘‘optimal-level’’ [MCDF(OL)] and ‘‘average-level’’ [MCDF(AL)] as well as with relativistic configuration-interaction (CIDF) methods are compared with experimental data. It can be seen that for highly ionized systems all three methods yield very close results, whereas for neutral systems the MCDF(OL) method is the most reliable. For neutral systems and short basis sets the MCDF(AL) results differ considerably with experiment and are very similar to those of the CIDF approach. This dfference is largely reduced if core-electron–valence-electron correlation is included in the core-polarization approximation.

• Received 18 September 1989

DOI:https://doi.org/10.1103/PhysRevA.41.2869