Probing the nonlocal resonance model of electron collisions with diatomic molecules*

The nonlocal resonance model [W. Domcke, Phys. Rep. 208, 97 (1991)] to nuclear dynamics of low-energy resonant collisions of electrons with molecules was successfully applied to many diatomics. We show how underlying assumptions of this theory can be tested using a simple model of the electron-molecule collisions with one electronic and one nuclear degree of freedom, which was introduced by the authors [Phys. Rev. A 73, 032721 (2006)] and which can be solved numerically exactly without the Born-Oppenheimer approximation. The basic result of our investigation is that the ``background'' contribution to the cross sections can be significant even for inelastic collisions such as vibrational excitation of the molecule F2. Moreover the Fano-Feshbach R-matrix theory [B.M. Nestmann, J. Phys. B 31, 3929 (1998)] which was proposed to provide parameters of the nonlocal resonance model has been recently tested within our model and its drawbacks are discussed.