Saddle-point technique for autoionizing states of the lithium atom. III. Low-lying triply excited resonances

Abstract

The energy, wave function, and radial parameters of the low-lying triply excited resonances of the lithium atom are calculated using a saddle-point technique. A total of eleven resonances with $^{2}P^{o},^{4}P^{e},^{2}D^{e},^{2}S^{e},^{2}P^{e}$, and $^{2}D^{o}$ symmetries are investigated. These results are used to identify the observed Auger spectra of R\o{}dbro, Bruch, and Bisgaard. If the identifications suggested here are correct, then the agreement between the results of the present work with those of the experiment is excellent. The oscillator strengths and transition energies of these resonances in an optical absorption or emission process are calculated. In order to compute these oscillator strengths, the energies and wave functions of the Li $1s2s2p^{4}P,1s2p2p^{2}P$, and $1s2s2s^{2}S$ states are also tabulated. The energies of the two bound states agree to within 0.013 eV with the highly accurate results in the literature. The result for the $^{2}S$ resonance agrees with the more recent experiments and lies well within the quoted experimental error.