Semiclassical initial value representation for multimode calculation of dissociative electron attachment processes

Dissociative electron attachment (DEA) to polyatomic molecules plays an important role in a vast variety of chemical processes that happen in nature and in industrial world. DEA calculations performed so far [1] were done either in approximation of one vibrational mode or in the local approximation which describes the nuclear motion in the intermediate resonance state by an effective Schroedinger equation with a local complex potential. In the present paper we develop a multimode theory which goes beyond the local approximation by employing the semiclassical initial value representation [2] for calculation of matrix elements of the Green operator for the nuclear motion. We apply this method to calculation of DEA to the CF$_3$Cl molecule with inclusion of the C-Cl symmetric stretch mode and the CF$_3$ umbrella mode. $^1$ I. I. Fabrikant \textit {et al.}, Adv. At., Mol.,Opt. Phys {\bf 66}, 545 (2017). $^2$ W. H. Miller, J. Phys. Chem. A {\bf 105}, 2942 (2001).