Molecular collisions : State-of-the-art calculations of inelastic collisions

We set up a framework for calculating in a precise and controlled way the collisional properties of several molecules of astrophysical meaning. The quantities that are relevant for astrophysics are rotational and vibrational quenching/excitation rates by means of collisions of H-2 with water and some organic molecules (HC3N, H2CO). We calculate those rates by means of successively determining a intermolecular potential energy surface and calculating inelastic cross sections and rates classically and/or quantum mechanically. These calculations are part of the European Union FP6 Molecular Universe program.