Non Franck-Condon effects in the photoionization of molecular nitrogen to the N+ A 2II state in the 19-34 eV photon energy region.
Photoionization to the N2+ A 2Πu state is studied using photoelectron spectroscopy. Experimentally, vibrational branching ratios for the v′=0–3 levels obtained for the first time in the 20–34 eV region, show strong non Franck–Condon effects around 22 eV. Using ab initio many body perturbation theory, branching ratios for ionization to the A 2Πu state are calculated. This study indicates that the F
