Theoretical studies of low-energy electron-CO2scattering: Total, elastic, and differential cross sections

We report the results of a theoretical study of electron scattering by CO[sub 2] at incident electron energies ranging from 0.25 to 10 eV using the complex Kohn variational method. These are the first fully [ital ab initio] calculations to accurately reproduce the two dominant features observed in experiment, namely, the dramatic rise in the integral cross sections below 2.0 eV and the resonance enhancement near 3.8 eV. Both of these effects are sensitive to the inclusion of electronic correlation effects involving long-range target polarization and short-range distortion. We have also carried out a preliminary study of effects of target vibrational motion in [sup 2][Pi][sub u] symmetry with an adiabatic nuclei treatment of the symmetric stretch mode. We find that this has a substantial effect on the width of the 3.8 eV resonance feature and gives results for both the integral elastic and total cross sections in excellent agreement with experiment. Our calculated differential elastic cross sections are also in good accord with recent experimental results. [copyright] [ital 1999] [ital The American Physical Society]