Semiclassical wave packet study of V-V energy transfer in highly vibrationally excited CO molecules

Application of a semiclassical wave packet approach to the study of vibrational energy transfer in collision between highly vibrationally excited diatomic molecules is discussed. The method uses a quantum mechanical description based on the solution to the time-dependent Schrodinger equation to describe the vibrational motions and a classical mechanical treatment for the rotational and translational motions. The quantum and classical dynamics are coupled through an effective Hamiltonian in which the classical degrees-of-freedom are propagated. The usefulness of the method is illustrated by computing rate coefficients for V-V energy transfer processes in CO-CO collisions in which one of the collision partners is kept in a very highly excited vibrational state. To the best of our knowledge, this is the first realistic dynamics study in which vibrational level as high as upsilon = 40 is considered in V-V energy transfer processes in CO molecules.