A b i n i t i o configuration interaction study of the valence states of O2

Configuration interaction calculations have been performed for the 62 electronic states of O2 arising from O atoms in the lowest 3P, 1D, and 1S states. The calculations used an extended one-particle basis set, and included internal and semi-internal electron correlation effects. Numerical values for potential curves are reported for all states. Detailed comparison with experiment and other calculations is made for the seven lowest bound states: X 3Σg−, a 1Δg, b 2Σg+, c 1Σu−, C 3Δu, A 3Σu+, and B 3Σu−. For these seven states the maximum error in the calculated spectroscopic constants Re, De, Te, and ωe are 0.04 Å, 0.4 eV, 0.2 eV, and 120 cm−1, respectively.