Nonlocal complex potential theory of dissociative electron attachment: Inclusion of two vibrational modes*

Dissociative electron attachment (DEA) process is important for many applications in plasma industry and radiation damage [1]. Theory of DEA to polyatomic molecules often includes a single vibrational mode in the target molecule, with all the other modes being ``frozen". In the local approximation [2] of DEA, the nuclear motion of the intermediate negative-ion state is described by a Schr\"{o}dinger equation with a local complex potential which is an approximation to a non-local energy-dependent complex operator [3]. Previous non-local DEA calculations assumed only one nuclear degree of freedom in the target molecule. In the present paper we extend the non-local theory by inclusion of two or more degrees of freedom in the target molecule. The theory is then applied to DEA to the CF$_3$Cl molecule by inclusion of the C-Cl symmetric stretch and CF$_3$ ``umbrella" modes. The DEA cross section for specific vibrational states and temperature-averaged cross sections are obtained and compared with the previous theoretical results an experiments. $^1$ I. I. Fabrikant \textit {et al.}, Adv. At., Mol.,Opt. Phys. {\bf 66}, 545 (2017). $^2$ D. T. Birtwistle and A. Herzenberg, J. Phys. B: At. Mol. Phys. {\bf 4}, 53 (1971). $^3$ J. N. Bardsley, J. Phys. B: At. Mol. Phys. {\bf 1}, 349 (1968)