Molecular collision processes. II. Excitation of the fine-structure transition of C+in collisions with H2(interstellar medium application)

For pt.I see ibid., vol.10, no.18, p.3665 (1977). Quantum-mechanical calculations of collisions between C + ions and para- and ortho-H 2 have been performed in order to determine the cross section for the C + 2p 1 P 1 2/ 0 - 2 P 3 2/ 0 fine-structure transition at thermal energies. The interaction potential, at long range, is derived from the usual perturbation theory expansions and, at short range, from available computations of the potential energy curves. The effects of coupling to excited rotational states of the H 2 molecule are investigated. The corresponding fine-structure cooling rate coefficients are tabulated over the temperature range 10