Photodissociation of polyatomic systems: non-adiabatic effects and conical intersections

Importance of non-adiabatic interactions and conical intersections are presented on two examples: the competitive photodissociation of bromoacetyl chloride and the different mechanisms for photodissociation of the vinoxy radical. This study is undertaken in relation with laser-molecular beam experiments and a detailed discussion is developed with regard to the critical regions of the potential energy surfaces of the states involved in the processes taking account of the conclusions extracted from experimental measurements. Quantum dynamical simulations in the framework of the constrained Hamiltonian methodology are exhibited in the case of bromoacetyl chloride.