Rotational excitation of HF in collision with He

We consider transitions for levels up to J=9 and for temperatures up to 300K. We use a new global 3D potential energy surface which we proposed recently and is the best available at the moment.

This surface exhibits two minima associated both with linear geometries (V=-43.70cm^-1^ for He-HF and V=-25.88cm^-1^ for He-FH). Close Coupling calculations are performed in the collision energy 10^-6^ to 2000cm^-1^ interval. Our results validate the estimate, by Neufeld et al. (1997ApJ...488L.141N), of the abundance of HF in the interstellar medium which was detected recently.