Photodissociation of triatomic molecules: Application of the R-matrix propagation methods to the calculation of bound-free Franck–Condon factors

We present a method for calculating Franck–Condon factors for the photodissociation of triatomic molecules. We use the R-matrix propagation techniques developed by Light and Walker for reactive scattering processes. The method is used to study the collinear dissociation of a model CO2 system. Franck–Condon overlaps are calculated for three different initial states and probabilities for populating particular vibrational levels of the CO fragments are obtained. We present results for a range of photon energies. We find that the partial cross sections exhibit a series of resonant or Fano line shapes. The structure in the cross sections depends sensitively on the initial vibrational state, but the peak values are not significantly effected.