Photodissociation as a quantum transition: Photofragment vibrational distributions of C₂N₂ (C̃ ¹Π _u predissociation

Polyatomic indirect photodissociation is treated as a quantum transition between quasidiscrete and dissociative (photofragment) states. Our adiabatic method is followed to describe the nuclear dynamics of the dissociative state. Ab initio MCHF excited electronic potential energy surfaces are constructed and used to determine heavy-particle dynamics. The theory is applied to single-photon predissociation of C2N2(C̃ 1Πu ) at 164, 158.7, and 153.6 nm to form CN(X 2Σ+) + CN(A 2Π). Theoretical predictions are found to be in good agreement with recent experimental product vibrational energy distributions. © 1987 American Institute of Physics.