The eikonal approximation to molecular photodissociation: Application to CH3I

The selfconsistent eikonal treatment is applied to the photodossociation of CH3 I by near ultraviolet light. A model based on two potential-energy surfaces is used as in previous studies, to compare our results with other treatments. State-to-state transition probabilities are calculated from eikonal wave functions constructed from classical trajectories and their divergence, using a recently developed procedure which avoids the generation of trajectory bundles. Numerical results have been obtained for cross sections versus light wavelength and for each vibrational state of the methyl fragment. Our results are in very good agreement with wave packet calculations. In addition, we have calculated these cross sections for several initial vibrational states of CH3 I, for some of which the total cross sections show several maxima.