Ab initio MO calculations have been carried out for the C(P-3) + N-2 reaction system. The reaction has been shown to pass through CNN, NCN, and cyclic c-NCN intermediates. The rate constants for the forward and reverse directions have been calculated with multichannel variational RRKM theory. We have also calculated the unimolecular rate constants for the NCN decomposition. The theoretically predicted heats of formation for NCN and CNN are in good agreement with recent experimental measurements.