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.

Near-Threshold and Resonance Effects in Rotationally Inelastic Scattering of DO with -H.

We present a combined experimental and theoretical study on the rotationally inelastic scattering of heavy water, DO, with -H. Crossed-molecular beam measurements are performed in the collision energy range between 10 and 100 cm, corresponding to the near-threshold regime in which scattering resonances are most pronounced. State-to-state excitation cross-sections are obtained by probing three low-lying rotational levels of DO using the REMPI technique.

Probing Low-Energy Resonances in Water-Hydrogen Inelastic Collisions.

Molecular scattering at collisional energies of the order of 10-100  cm^{-1} (corresponding to kinetic temperatures in the 15-150 K range) provides insight into the details of the scattering process and, in particular, of the various resonances that appear in inelastic cross sections. In this Letter, we present a detailed experimental and theoretical study of the rotationally inelastic scattering of ground-state ortho-D_{2}O by ground-state para-H_{2} in the threshold region of the D_{2}O(0_{00}→2_{02}) transition at 35.9  cm^{-1}.