Theoretical study of quantum molecular reaction dynamics and of the effects of intense laser radiation on a diatomic molecule

Within the very broad field of molecular dynamics, the author concentrates on two simple yet important systems. The systems are simple enough so that they are adequately described with a single Born-Oppenheimer potential energy surface and that the dynamics can be calculated accurately. They are important because they give insight into solving more complicated systems. First, H + H2 reactive scattering is discussed. An exact formalism for atom-diatom reactive scattering is presented that avoids the problem of finding a coordinate system appropriate for both reactants and products. This is done by using an over complete basis where expansion functions are included that are localized in each arrangement channel. The interaction between different arrangements is described using an energy independent nonlocal exchange kernel. Computational results are given for collinear H + H2 reactive scattering that agree very well with previous calculations. The second system studied is an isolated HF molecule in an intense laser field. Using classical trajectories and quantum dynamics, energy absorbed and transition probabilities as a function of the laser pulse time are examined and also averaged over the pulse time. Calculations are performed for both rotating and nonrotating HF