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

We consider 51 odd-parity configurations of Pb I utilizing all data av ailable from absorption and emission spectroscopy measurements, photoi onization experiments, and ejected-electron spectroscopy. These includ e detailed results of our earlier laser spectroscopic studies of the 6 s(2)6pns, 6s(2)6pnd, and 6s(2)6png Rydberg levels [P. Buch, J. Nelless en, and W. Ertmer, Phys. Scr. 38, 664 (1988)]. The analysis has been p erformed with the aid of a linked-parameter method of level-fitting ca lculations 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 assi gnments of 242 odd parity electronic energy levels are given. Eigenvec tors obtained;in these calculations can be used to calculate the value s of other physical observables with high precision. In addition, we h ave also made appropriate pseudorelativistic Hartree-Fock ab initio ca lculations of level structure, oscillator strengths, and autoionizatio n widths for procedural guidance and comparison purposes.