Rotational excitation and de-excitation of CH⁺ molecules by ⁴He atoms

Institut des Sciences Moléculaires, UMR5255-CNRS, Université de Bordeaux, France e-mail: t.stoecklin@ism.u-bordeaux1.fr

Received: 22 June 2009
Accepted: 11 November 2009

Abstract

We present a quantum mechanical investigation of rotational energy transfer in cold collisions of CH⁺ with ⁴He atoms. We use a global 3D potential energy surface obtained using the reproducing Kernel Hilbert Space (RKHS) method. Rotational deactivation transition cross-sections are performed for collision energy ranging from 10^-6 to 3000 cm^-1 and the corresponding rotational deactivation and excitation rate coefficients are evaluated for the transitions of levels up to j = 5 and temperatures up to 500 K. We also discuss the validity of the rigid rotor approximation for this collision.