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 O-2(+) have also been studied at the complete basis set level and subsequently analytically modelled. In the case of O-2(+), 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 1 cm(-1). Spin orbit + relativistic effects have also been taken into account for the O-2(+) ion. (C) 2017 Elsevier B.V. All rights reserved.