Accurate ab initio treatment of low-energy electron collisions with polyatomic molecules: Resonant electron-formaldehyde scattering.

Abstract

We report the first results of a fully ab initio treatment of the scattering of low-energy electrons by formaldehyde. The calculations are carried out using the complex Kohn variational method, which is an anomaly-free algebraic variational procedure, and are implemented by a combination of analytic and adaptive, three-dimensional quadrature techniques. The calculations reveal a low-energy shape resonance of $^{2}\mathrm{B}_{1}$ symmetry, which is prominent in the elastic differential cross section only at large scattering angles, and which has been observed experimentally. Its position is sensitive to target distortion effects which are accurately handled by inclusion of an optical potential calculated from first principles.