Multireference Cl calculations are reported for OH(2Π). OH+ (3Σ-), and OH2+ (4Σ-) using several basis sets. Ionization potentials derived from the potential curves are compared to previous calculations and to experimental values. We show that the errors obtained from the calculations can be traced to the difficulty in obtaining an accurate treatment of the ionization energy of the oxygen atom. No experimental artifact needs to be invoked to explain the discrepancy with the experimental results.
Chemical Physics Letters
Department of Chemistry

Wright, J.S, Barclay, V., & Kruus, E. (1985). MRD Cl calculation of the first and second ionization potential of OH. Chemical Physics Letters, 122(3), 214–218. doi:10.1016/0009-2614(85)80565-0