Abstract The most stable geometry and its energy is computed for the doubly-charged cation H 2 COH 2+ 2 at the Hartree—Fock level, using a restricted determinant. Once that point was located, the stability of the dication for the process of deprotonation was computed at the same level of approximation. A barrier is found and the implications of this fact are discussed. In order to know the basis set dependence, the whole study was done at the STO-3G, 4-31G and 4-31G* basis levels.