2013A&A...556A..82A

The present paper focuses on the calculation of the collision rate coefficients for rotational excitation of the ¹²CF⁺ and its isotopologue ¹³CF⁺ by He for temperature ranging from 10 to 300 K. A two-dimentional (2D) potential energy surface (PES) of the CF⁺(X¹Σ⁺)-He(¹S) system is calculated at the ab initio coupled cluster with single, double, and perturbative triple excitation level of theory with the aug-cc-pV5Z basis set. The basis set superposition errors were taken into account in our computation. Dynamical calculations of state-to-state rotational integral cross sections of the CF⁺ by collision with He were performed using the close-coupling method. The PES presents a global minimum of ∼212cm^–1 below the CF⁺-He dissociation limit. Collisional cross sections among the first 11 rotational levels of CF⁺ were calculated for total energies up to 1500cm^–1. Downward rate coefficients between the rotational levels were calculated for temperature ranging from 10 to 300K. A propensity toward an even parity of ΔJ is observed.