Is N-protonated hydrogen isocyanide, H2NC+, an observable interstellar species?

Ab initio molecular orbital theory is used to examine the singlet and triplet potential energy surfaces for the CH2N+ system. The results confirm those of earlier studies which suggested that the singlet H2NC+ isomer could be formed via the corresponding triplet isomer. Also, it is shown that the reaction HCN+ + H2 might lead to this metastable isomer without invoking the triplet species. The best test of the hypothesis that this molecule can be formed by gas phase, ion molecule reactions and may be an important precursor in the interstellar synthesis of HCN and HNC is to search for it in space. To this end, theoretical predictions are made of its rotational frequencies and its vibrational frequencies and intensities to serve as a guide to laboratory spectroscopists and radioastronomers.