2019MNRAS.486..414L

Rate coefficients for state-to-state rotational transitions of C₃N^– induced by collision with both ortho- and para-H₂ are presented. Quantum calculations are performed at the close-coupling level using the uniform J-shifting method and a new potential energy surface specially developed for this purpose. Rate coefficients are obtained for state-to-state transitions among the first 28 rotational levels of C₃N^– and for temperatures ranging from 10 to 300 K. The para-H₂ rate coefficients are shown to differ strongly from the mass-scaled He rate coefficients previously computed. The ortho- and para-H₂ rate coefficients are very similar, as it was already observed for the rotational transitions of CN^– and C₆H^–. There is also an unexpected similarity between the rate coefficients of the rotational de-excitations of CN^–, C₃N^–, and C₆H^–. This may open door to quantitative extrapolations of the rate coefficients for larger anions.