title: Photochemistry in a dense manifold of electronic states: photodissociation of CH2ClBr.
abstract: We report electronically nonadiabatic dynamics calculations including spin-orbit coupling for the photodissociation of CH(2)ClBr to yield Cl((2)P(3∕2)), Cl((2)P(1∕2)), Br((2)P(3∕2)), and Br((2)P(1∕2)). The potential energy is a 24 × 24 matrix (divided up here into four 6 × 6 blocks in a first approximation to the problem), in a spin-coupled fully diabatic representation obtained by combining the spin-free fourfold way with single-center spin-orbit coupling constants. The spin-free calculations are carried out by multiconfiguration quasidegenerate perturbation theory, and the fully diabatic potentials including spin-orbit coupling are fit to a matrix reactive force field. The dynamics are carried out by the coherent switches with decay of mixing method in the diabatic representation. The results show qualitative agreement with experiment.
authors.affiliation: Department of Chemistry, University of Coimbra, Coimbra, Portugal. rosendo.valero@gmail.com
authors.forename: Rosendo
authors.initials: R
authors.lastname: Valero
authors.forename: Donald G
authors.initials: DG
authors.lastname: Truhlar