Core effects on transition energies for 3dk configurations in Tungsten ions

Abstract

All energy levels of the 3dk, k = 1,2,., 8, 9, configurations for tungsten ions, computed using the GRASP2K fully relativistic code based on the variational multiconfiguration Dirac-Hartree-Fock method, are reported. Included in the calculations are valence correlation where all 3s, 3p, 3d orbitals are considered to be valence orbitals, as well as core-valence and core-core effects from the 2s, 2p subshells. Results are compared with other recent theory and with levels obtained from the wavelengths of lines observed in the experimental spectra. It is shown that the core correlation effects considerably reduce the disagreement with levels linked directly to observed wavelengths, but may differ significantly from the NIST levels, where an unknown shift of the levels could not be determined from experimental wavelengths. For low values of k, levels were in good agreement with relativistic many-body perturbation levels, but for 2 < k < 8, the present results were in better agreement with observation.