The present study was initiated by the recent observation of the novel molecular species SeO2+ in the gas phase by Franzreb and Williams at Arizona State University. Here we report a very detailed theoretical investigation of the low-lying electronic states of SeO2+. Our results show that the potential energy surfaces of the dicationic electronic states have high potential barriers with respect to dissociation, so this dication can exist in the gas phase as a long-lived metastable molecule. The potential energy curves are used to predict the double photoionization spectrum of SeO and to derive a set of spectroscopic parameters for the bound states of SeO2+. (C) 2011 Elsevier B.V. All rights reserved.