Highly Correlated Electronic Structure Calculations of the He–C3   van der Waals Complex and Collision-Induced Rotational Transitions of C3

• Published in: The journal of physical chemistry. A, Molecules, spectroscopy, kinetics, environment, & general theory Vol. 118; no. 33; pp. 6351 - 6360
• Main Authors: Smith, Daniel G. A, Patkowski, Konrad, Trinh, Duy, Balakrishnan, N, Lee, Teck-Ghee, Forrey, Robert C, Yang, B. H, Stancil, P. C
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 21.08.2014
• ISSN: 1089-5639; 1520-5215
• DOI: 10.1021/jp412048w

An accurate 2D ab initio potential energy surface of the He–C3 collisional system is calculated using the supermolecular coupled-cluster method with up to perturbative quadruple excitations, CCSDT(Q). This interaction potential is then incorporated in full close-coupling calculations of rotational excitation/de-excitation cross sections in He + C3 collisions for rotational levels j = 0, 2, ..., 10 and collision energies up to 1000 cm–1. Corresponding rate coefficients are reported for temperature between 1 and 100 K. Results are found to be in excellent agreement with available theoretical data that were restricted to the temperature range of 5–15 K. Implications of the computed rate coefficients to astrophysical models of C3 and carbon clusters in interstellar and circumstellar environments are discussed.