Temperature dependence of the rate coefficient of formation of CN radical from C + NH

7 pags., 6 figs.Rate coefficients of the complex-forming C + NH→H + CN reaction have been calculated at temperatures ranging from 5 K to 800 K using quasi-classical trajectories on a potential energy surface which accurately describes the attractive long-range interaction, along with results using two capture models. In contrast with the constant value recommended in astrochemical databases, a steep decrease of the rates has been found up to 150 K, and then they tends to be nearly constant. Such behavior is analyzed in terms of the rovibrational state-selected rate coefficients and cross sections singling out the role played by the rotational excitation of the initial diatom. The effect of the electronic degeneracy is also discussed.We thank Prof. A.J.C. Varandas for making available to us the DMBE potential energy surface and the Oklahoma University Supercomputing Center for Education & Research (OSCER) and the European Grid Infrastructure (EGI) through COMPCHEM Virtual Organization for providing computing resources and services. The authors also acknowledge the financial support from the MINECO/FEDER of Spain under grants PGC2018-096444-B-I00, PID2019-107115 GB-C21 and FIS2017-83473-C