Configuration mixing in singly-ionized platinum group elements I. Low odd configurations of Hf II, Ta II and W II

Abstract

The odd energy levels of Hf II, Ta II and W II have been investigated by means of the Slater-Condon parametric method. This led us to elimination of fortuitous levels reported in earlier analyses, to revision of J-values and the finding of 23 new levels in Ta II. The configuration mixing is very strong in the groups 5dN−16s6p + 5dN−26s6p + 5dN−36s26p, the latter configuration being generally unrecognizable. Very few low odd levels are still unknown in these spectra.