Electron scattering with open-shell molecules: R-matrix method

Abstract

Many molecules with an even number of electrons belong to open-shell systems due to π 2 ground state electronic configuration. This configuration gives rise to three low-lying states X 3 Σ −, a Δ 1 and b 1 Σ +. The inclusion of these target states in a trial wave function of the entire scattering system have important implications in the resonances that may be detected in these open-shell molecules. Various molecules like O2, PX (X = H and halogens), SO, Si2, BF have π 2 ground state configuration. The R-matrix method is a well established ab initio formalism to calculate differential, integral and momentum-transfer cross sections for the elastic scattering of electrons by molecules. We have calculated these cross sections for PH and SO molecules in the incident electron energy range 0–10 eV. The results are obtained by using the R-matrix method in which the closecoupling expansion of the wave function of the scattering system includes only the ground state. This target state is described by configuration interaction wave function that includes correlation effects. The cross section for electron impact on PH and SO are presented.