Induced rotational excitation of the fluoromethylidynium 12CF+ and 13CF+ through collision with helium

Aims. The present paper focuses on the calculation of the collision rate coefficients for rotational excitation of the (CF+)-C-12 and its isotopologue (CF+)-C-13 by He for temperature ranging from 10 to 300 K. Methods. A two-dimentional (2D) potential energy surface (PES) of the CF+ (X-1 Sigma(+))-He(S-1) 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. Results. The PES presents a global minimum of similar to 212 cm(-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 1500 cm(-1). Downward rate coefficients between the rotational levels were calculated for temperature ranging from 10 to 300 K. A propensity toward an even parity of Delta J is observed.