R-matrix calculation of integral and differential cross sections for low-energy electron impact excitations of N2 molecule

Abstract

Low-energy electron impact excitations of N$_2$ molecules are studied using the fixed-bond R-matrix method based on state-averaged complete active space SCF orbitals. Thirteen target electronic states of N$_2$ are included in the model within a valence configuration interaction representations of the target states. Integrated as well as differential cross sections of the $A^{3} \Sigma_{u}^{+}$, $B^{3} \Pi_{g}$, $W^{3} \Delta_{u}$, ${B'}^{3} \Sigma_{u}^{-}$, ${a'}^{1} \Sigma_{u}^{-}$, $a^{1} \Pi_{g}$, $w^{1} \Delta_{u}$ and $C^{3} \Pi_{u}$ states are calculated and compared with the previous experimental measurements. These excitations, especially of the higher four states, have not been studied enough theoretically in the previous literature. In general, good agreements are observed both in the integrated and differential cross sections. However, some discrepancies are seen in the integrated cross sections of the $A^{3} \Sigma_{u}^{+}$ and $C^{3} \Pi_{u}$ states, especially around a peak structure.