Temperature dependence of the fine-structure resolved rate coefficients for collisions of O2(X3Σg-) with He

Rotational excitation of the O-2(X-3 Sigma(-)(g)) with He is investigated. The calculations are based on the potential energy surface of Groenenboom and Struniewicz [J. Chem. Phys. 113, 9562 (2000)]. Close coupling calculations of the collisional excitation cross sections of the fine-structure levels of O-2 by He are calculated for energies up to 2500 cm(-1) which yield, after thermal average, rate coefficients up to 350 K. The exact level splitting is taken into account. The propensity rules between fine-structure levels are studied and it is shown that F-conserving cross sections are much larger, especially for high-N rotational levels, than F-changing cross sections, as expected from theoretical considerations. The rate coefficients are almost independent of the rotational quantum number of the O-2 molecule for F-conserving transitions. The new rate coefficients can induce important consequences on astrophysical modeling.