Induced rotational excitation of the fluoromethylidynium 12CF+ and 13CF+ through collision with helium
1 Laboratoire de Spectroscopie Atomique Moléculaire et Applications, Faculté des Sciences, Université Tunis el Manar, 2092 Tunis, Tunisie
2 Université Paris-Est, Laboratoire Modélisation et Simulation Multi-Échelle, MSME UMR 8208 CNRS, 5 Bd Descartes, 77454 Marne-La-Vallée, France
Received: 14 December 2012
Accepted: 11 June 2013
Aims. 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.
Methods. 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.
Results. The PES presents a global minimum of ~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 ΔJ is observed.
Key words: molecular data / molecular processes / ISM: molecules
© ESO, 2013