The elastic scattering of electrons from CO2 molecules .2. Molecular features and spatial symmetries of some resonant states

The same quality target wavefunction employed to carry out close-coupling (CC) scattering calculations in a previous paper by Gianturco and Stoecklin is now used to generate effective adiabatic potentials within a model treatment of the full interaction between the electron and the target molecule. A set of approximate diabatic potentials is then obtained by a series of sector diagonalizations. The present study clearly shows the presence of three shape resonance states for three of the contributing irreducible representations (IR), Sigma(g), Sigma(u) and Pi(u), which the present model calculations locate rather close to the energies given by the earlier, exact CC calculations by Gianturco and Stoecklin. The molecular nature of the resonant scattering states is further analysed in terms of their spatial structures and of the non-adiabatic couplings between potential curves induced by the anisotropy of the electron-molecule interactions. The interplay between the specific symmetry of the fixed-nuclei target geometry and the strength of the anisotropic bound-continuum interaction is shown to control, within each IR, the important features of the resonances.