Low-energy resonant structures in electron scattering from C20 fullerene

We have performed the first ab initio computational investigation of the elastic scattering of electrons by the isolated cluster which was described with its symmetry lowered (due to Jahn-Teller distortion) to the C-2 and C-i point groups. The energy range considered was 1-10 eV. The geometry and electronic energy of the molecule were taken to be those of its ground state. The total and partial cross sections were calculated through a coupled-channel dynamics with inclusion of a parameter-free model exchange and correlation-polarization potentials. The scattering process has been found to exhibit a rather complex resonant structure due to the special "hollow" framework of the molecular cage. One distinguishing feature of the cross sections is the presence of strong near-threshold peaks which we attribute to a series of C-20(-) metastable negative ions. The present results therefore provide a benchmark calculation which could be of guidance to future experiments on the very recently produced fullerene C-20 species. In fact, the analysis carried out in the present work allows us to assign each scattering resonance to a specific molecular state, their symmetries and parameters obtained from our calculations. (C) 2002 American Institute of Physics.