Need of LS-Dependent Energy Parameters in the Second Spectra of the Fifth-Group Elements*

In the analysis of As ii, the usual Slater–Condon treatment was found unsatisfactory for the multiconfiguration group 4s4p3–4p4d–4p5d–4p6d–4p7s. It was found that when LS-dependent parameters were introduced there was a substantial improvement of the agreement between experimental and calculated energy levels and for the Landé g factors as well. We carried out Hartree–Fock (HF) solutions for each term of this multiconfiguration and obtained convincing evidence of the necessity for LS-dependent parameters. In N ii, P ii, Sb 1i, and Bi ii, we found the same pattern to hold in the HF solutions for the sp3 and the corresponding first three pd configurations.