Full-dimensional quantum dynamics of rovibrationally inelastic scattering between CN and H2

• Published in: The Journal of chemical physics 2016-12, Vol.145 (22), p.224307-224307
• Main Authors: Yang, Benhui, Wang, X. H., Stancil, P. C., Bowman, J. M., Balakrishnan, N., Forrey, R. C.
• Format: Article
• Language: English
• Subjects: Analytic functions; Astronomical models; Collision dynamics; Inelastic scattering; Potential energy; Quenching
• ISSN: 0021-9606; 1089-7690
• DOI: 10.1063/1.4971322

We report six-dimensional (6D) potential energy surface (PES) and rovibrational scattering calculations for the CN–H2 collision system. The PES was computed using the high-level ab initio spin-restricted coupled-cluster with single, double, and perturbative triple excitations-F12B method and fitted to an analytic function using an invariant polynomial method in 6D. Quantum close-coupling calculations are reported for rotational transitions in CN by H2 and D2 collisions in 6D as well as four-dimensional (4D) within a rigid rotor model for collision energies of 1.0-1500 cm−1. Comparisons with experimental data and previous 4D calculations are presented for CN rotational levels j 1 = 4 and 11. For the first time, rovibrational quenching cross sections and rate coefficients of CN (v 1 = 1,j 1 = 0) in collisions with para- and ortho-H2 are also reported in full-dimension. Agreement for pure rotational transitions is found to be good, but no experimental data on rovibrational collisional quenching for CN–H2 are available. Applications of the current rotational and rovibrational rate coefficients in astrophysical modeling are briefly discussed.