We have examined available data for the odd-parity energy-level structures in Zr and Hf, stimulated by the designations of four predicted 6d7${\mathit{s}}^2$7p levels in the homologous atom rutherfordium (Rf, Z=104) by Eliav et al. [Phys. Rev. Lett. 74, 1079 (1995)]. We point out some errors and deficiencies in the Zr data and give the results of Hartree-Fock calculations for Hf 5d6${\mathit{s}}^2$6p and Rf 6d7${\mathit{s}}^2$7p levels. Configuration interactions within the (d+s${)}^3$p complexes were included. The resulting eigenvectors allow meaningful LS-coupling designations for most of the levels belonging mainly to Hf 5d6${\mathit{s}}^2$6p and for most of the predicted Rf levels belonging mainly to 6d7${\mathit{s}}^2$7p. Some changes in the designations assigned to these levels in the literature are suggested: in particular, the lowest level of both Hf 5d6${\mathit{s}}^2$6p and Rf 6d7${\mathit{s}}^2$7p is most appropriately designated ${}_{}{}^3{}_{}{}^{}\mathrm{F}_2^{\mathit{o}}{}_{}{}^{}$. We point out the need for systematic whole-row studies of the low odd-parity configurations in 4d- and 5d-shell spectra. © 1996 The American Physical Society.

• Received 11 October 1995

DOI:https://doi.org/10.1103/PhysRevA.53.1911