Interaction of 4p54dN+1 and 4p64dN−14f configurations and its influence on the photoexcitation and emission spectra in the isoelectronic and isonuclear sequences

Abstract

The strong interaction of 4p54dN+1 + 4p64dN−14f configurations and its influence on the photoexcitation and emission spectra corresponding to the excitations from the ground level of 4p64dN have been considered. The results are presented for the isoelectronic sequences from the ionization degree q = 5 up to q = 29–37 as well as for the isonuclear sequences of Snq+ and Wq+. It is shown that depending on the number of 4d electrons, the variation of spectra in the isoelectronic sequences corresponds to three different types. At N = 4 and N = 6–9, the strong concentration of lines takes place in the whole isoelectronic sequence, except for small ionization degrees. At N ⩽ 3, the width of photoexcitation and emission spectra also obtains a relatively larger value at small ionization degrees, decreases with ionization degree rising, but tends to increase again at large ionization degrees. In the whole isoelectronic sequence, a very narrow group of a few intense lines is obtained for N = 5. The transitions from the excited levels mainly proceed to the lowest level of the ground configuration; it is the reason for the similarity of photoexcitation and emission spectra. The quenching of many lines and the concentration of line strengths in a few transitions indicate the existence of some wavefunction basis with strict selection rules for dipole transitions.