Electronic excitation of molecular hydrogen using the R-matrix method

Abstract

Calculations are presented for electron-H₂ collisions for energies up to 25 eV. Excitation from the ground, X ¹ Sigma _g⁺, to the lowest six excited electronic states, b ³ Sigma _u⁺, a ³ Sigma _g⁺, c ³ Pi _u, B ¹ Sigma _u⁺, E, F ¹ Sigma _g⁺ and C ¹ Pi _u, is explicitly considered for all total symmetries up to and including ² Phi _g. The target states are represented using a full configuration interaction treatment within a basis of Slater-type orbitals optimized to give accurate vertical excitation energies. Results are presented for eigenphase sums, in which the resonant and other features are analysed, as well as total electronic excitation cross sections. Extensive comparison is made with the available experimental data. In contrast to many previous ab initio calculations the results are in good agreement with the observed electronic excitation cross sections for all the processes considered.