Rotational quenching of monofluorides in a cryogenic helium bath

Abstract

Buffer gas cooling, one of the most relevant direct cooling techniques for cooling molecules, relies on dissipating the energy of the molecule via collisions with a buffer gas. The cooling efficiency hinges on the molecule-atom scattering properties, concretely, on the transport properties. This work presents a global study on the interactions, collision dynamics, and transport properties of monofluoride molecules (X–F), with X being a metal, in the presence of a cold He buffer gas. The interactions are calculated using ab initio quantum chemistry methods, and the dynamics is treated fully quantal, assuming the monofluoride molecule is a rigid rotor. The resulting thermalization and rotational quenching rates are analyzed in light of the distorted-wave Born approximation, yielding an explanation based on the elemental physical properties of the molecule under consideration. Therefore, our findings contribute to understanding the rotational quenching of molecules in a cold buffer gas.