Systematically improved local complex potential approximation for the dynamics of electron-molecule collision complexes

Within the time-dependent formulation of the projection-operator theory of resonant electron-molecule scattering, systematic corrections to the local complex potential approximation can be derived. In this work the performance of the first-order corrected local approximation is assessed in comparison with the standard local approximation and exact results for two representative models of electron-molecule shape resonances. The results shed light on the importance of short-time nonexponential decay effects in resonant electron-molecule scattering. The first-order corrected local theory is shown to yield more accurate results than the conventional local approximation, without requiring additional computational effort.