STUDY OF ELECTRON-SCATTERING BY N2O USING THE POLYATOMIC R-MATRIX METHOD

We present results of ab initio calculations for electron-N2O scatteri ng using the polyatomic R-matrix method. We consider scattering energi es from 0 to 20 eV. Our calculations demonstrate that the low-energy s hape resonance just above 2 eV is due to a (2) Pi state of the negativ e ion. A broad 2 Sigma resonance is also found at higher energy (simil ar to 8 eV). Calculations are reported for static exchange, static exc hange with polarization, and correlated wavefunction levels of approxi mation. Our calculations are the first to use highly correlated wavefu nctions in R-matrix calculations for polyatomic targets, where such a treatment is necessary to get an accurate description of the resonant scattering process. The calculated integral elastic scattering cross s ection is found to be in good agreement with experimental results.