Electron-Molecule Elastic Scattering: A Study Using the Configuration Interaction Method and Model Potentials

Abstract In this work, the theory of electron-molecule scattering and the influence of model potentials on improving differential cross-section (DCS) results are addressed. Unlike the treatment that uses the Hartree-Fock (HF) approximation, the Configuration Interaction method (CI) is employed to treat the target and obtain the static and exchange potentials. Using CI, the influence and behavior of the correlation-polarization model potential proposed by Padial and Norcross, as well as the potential called free parameter B, are analyzed in the calculation of DCS for elastic e–N 2 scattering, with in the energy range of 5 eV to 20 eV. By comparing the results with experimental data and other theoretical results, it is shown that, although the Padial and Norcross potential is widely used in conjunction with HF and leads to satisfactory results in this case, its use with the CI method leads to unsatisfactory results, particularly for low scattering angles. On the other hand, the free parameter B potential appears to be more appropriate for including polarization effects, with no need for corrections related to electron correlation. The Lippmann-Schwinger equation, applied to scattering theory, is solved using the iterative variational method of Schwinger (SVIM), and in the CI calculation, single and double excitations are included.