The Condon reflection principle in collision dynamics

Publisher Website
Google Scholar
Abstract
The final internal state distributions obtained by collision dynamics and electronic spectroscopy are shown, by semi-classical arguments, to have a common origin in the properties of the relevant classical transformation in phase space. Both cases allow for the development of a Condon reflection spectrum, which mirrors the shape of the initial internal wavefunction, ultimately because the initial classical orbit encloses an area of (2n 1 + 1)πħ, which is conserved during the transition. The appearance of such structure is therefore independent of any specific Franck-Condon feature in the scattering mechanism; but it is shown to require a direct rather than a compound mechanism, and the absence of significant competition between different channels (reactive, inelastic and quenching). Such structure may in principle be observed in any type of channel, but the absence of sufficient interaction may preclude its observation in purely inelastic scattering except at very high collision energies. Cases suggested for experimental investigation are the quenching of Hg(3P0) by CO(v ≥ 1) and the exothermic reactions H + XY(v ≥ 1), where X and Y are halogen atoms.