T. Tanaka et al., THRESHOLD PHOTOELECTRON-SPECTRUM OF O-2 IN 31-34 EV REGION, Journal of electron spectroscopy and related phenomena, 79, 1996, pp. 507-509
High resolution threshold photoelectron spectra of O-2 were obtained i
n the region of 31-34 eV. Three vibrational progressions were observed
. These structures are assigned to two ionic Rydberg states converging
to the O-2(2+) ground state and to a valence state.