Vibrational Relaxation of DO Induced by Collision with He: A Rigid Bender Close Coupling Study.

The vibrational relaxation of the first excited bending state of DO induced by collision with He is studied at the close coupling level and using the Rigid Bender approximation. A new 4D potential energy surface is calculated and reported for this system. It is then used to determine the low-lying bound states of the DO-He van der Waals complex and to perform scattering calculations.

Scattering resonances in the rotational excitation of HDO by Ne and -H: theory and experiment.

The rotational excitation of a singly deuterated water molecule (HDO) by a heavy atom (Ne) and a light diatomic molecule (H) is investigated theoretically and experimentally in the near-threshold regime. Crossed-molecular-beam measurements with a variable crossing angle are compared to close-coupling calculations based on high-accuracy potential energy surfaces. The two lowest rotational transitions, 0 → 1 and 0 → 1, are probed in detail and a good agreement between theory and experiment is observed for both transitions in the case of HDO + Ne, where scattering resonances are however blurred out experimentally.

Quantum study of the rovibrational relaxation of HF by collision with He on a new potential energy surface.

The HF molecule is considered the main reservoir of fluorine in the interstellar medium (ISM). Also, the interactions of this molecule with the most common atoms and molecules in the ISM have attracted great interest from the astrochemical community. Collisions between HF and helium have recently caused controversy following a study using a two-dimensional SAPT potential energy surface (PES) that exhibited large discrepancies with previous scattering calculations based on more recent potentials.

A Rigid Bender Study of the Bending Relaxation of HO and DO by Collisions with Ar.

The bending relaxation of HO and DO by collisions with Ar is studied at the Close Coupling level. Two new 4D PES are developed for these two systems. They are tested by performing rigid rotor calculations as well as by computing the DO-Ar bound states.

Bending Relaxation of H O by Collision with Para- and Ortho-H.

We extend our recent theoretical work on the bending relaxation of H O in collisions with H by including the three water modes of vibration coupled with rotation, as well as the rotation of H . Our full quantum close-coupling method (excluding the H vibration) is combined with a high-accuracy nine-dimensional potential energy surface. The collisions of para-H O and ortho-H O with the two spin modifications of H are considered and compared for several initial states of H O.