The 4f¹³5f Configuration in the Isoelectronic Sequence of Yb III

Abstract

Energy levels of the configuration 4f135f have been observed for the first time in the spectra of Lu IV, Hf V, Ta VI, and W VII and have been interpreted by means of the Slater-Condon theory. The relative positions of two perturbing configurations 4f125d2 and 4f145p55f are discussed. The jj coupling scheme provides the best average purity for the labeling of the levels. Three hundred seventy-seven lines have been classified in these four spectra.