THE ROLE OF AUTOIONIZATION IN MOLECULAR PHOTOELECTRON SPECTROSCOPY

$^{1}$P. Natalis and J. E. Collin, Chem. Phys. Lett. 2, 414 (1968).""Author Institution: Department of Chemistry, Yale UniversityThe Fano configuration interaction theory of autoionization is used to calculate partial photoionization cross-sections for production of diatomic ions in specific vibrational states. The anomalous vibrational distribution in the photoelectron spectrum of $O_{2}$ excited with the neon resonance $line^{1}$ is explained. The vibrational distribution in $O^{+}_{2}(X^{2} \Pi_{g}$) is calculated for both a uniform excitation continuum and for the solar vacuum-ultraviolet spectrum as an excitation source, with the contribution from autoionization of the upper states of the Hopfield bands of $O_{2}$ explicitly included. About 5% of the $O^{+}_{2}$ produced by solar photoionization has more than 1 eV of vibrational energy