Accurate ab initio potential for [formula omitted]: CBS extrapolated energies and direct-fit diatomic curves

Abstract

A potential energy surface is reported at the complete basis set limit for the ground electronic state of HO2+ via a four dimensional interpolation in relaxed hyperspherical coordinates. The dissociated products OH+ and O2+ have also been studied at the complete basis set level and subsequently analytically modelled. In the case of O2+, the vibrational states predicted from the model potential have also been directly included in the fit. The potential form so obtained matches the RKR levels with a root mean square deviation below 1cm-1. Spin orbit + relativistic effects have also been taken into account for the O2+ ion.