Coulomb explosion imaging and the CH2+ molecule

The average distribution of bending angles for CH2+ molecules at 300 K has previously been determined using Coulomb explosion imaging (CEI). We calculate this distribution using our ab initio potential energy curves for the pair of Renner interacting ground state potentials, and we obtain a distribution that is significant over a narrower range of bending angles. Excited electronic states are too high in energy to explain this discrepancy. If the CEI result has enough precision, this would imply that our ab initio potentials are in error, and we show by how much. Experimentally determined bending energies would test this definitively.