We report calculations of vibrationally resolved cross sections and photoelectron angular distributions for photoionization of O2leading to theX 2&Pgr;g(&ngr;+=0–4) states of O+2using Hartree–Fock continuum photoelectron orbitals. These studies were motivated by recent results which show that a &sgr;ushape resonance plays a dominant role in producing non‐Franck–Condon vibrational distributions in resonant multiphoton ionization of O2via theC 3&Pgr;g(1&pgr;g3s&sgr;g) Rydberg state. In the present study, we investigate how this shape resonance influences photoionization dynamics in single‐photon ionization. Below 21 eV photon energy, we find significant non‐Franck–Condon effects in the vibrational branching ratios as well as in the vibrationally resolved photoelectron angular distributions. Substantial autoionization hinders a direct comparison between theory and experiment.
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