MEASUREMENT AND INTERPRETATION OF THE ODD-PARITY LEVELS OF PB-I

We consider 51 odd-parity configurations of Pb I utilizing all data available from absorption and emission spectroscopy measurements, photoionization experiments, and ejected-electron spectroscopy. These include detailed results of our earlier laser spectroscopic studies of the 6s(2)6pns, 6s(2)6pnd, and 6s(2)6png Rydberg levels [P. Buch, J. Nellessen, and W. Ertmer, Phys. Scr. 38, 664 (1988)]. The analysis has been performed with the aid of a linked-parameter method of level-fitting calculations in a large multiconfiguration basis. New identifications of the 6s6p(3) levels are proposed and reasons for their assignment are presented. On the basis of our level-fitting calculations precise assignments of 242 odd parity electronic energy levels are given. Eigenvectors obtained;in these calculations can be used to calculate the values of other physical observables with high precision. In addition, we have also made appropriate pseudorelativistic Hartree-Fock ab initio calculations of level structure, oscillator strengths, and autoionization widths for procedural guidance and comparison purposes.