Resonances in the electronic excitation of molecular hydrogen

Ab initio R-matrix scattering calculations are presented for electron-H2 collisions for energies up to 30 eV. Excitation from the ground state, X 1Σg+, to five accurately represented, low-lying electronic states, b 3Σu+, a 3Σg+, B 1Σu+, c 3Πu, and C 1Πu, is explicitly considered. An attempt is made to rationalize the wealth of experimental data. Resonance structures similar to those assigned experimentally to the a and c series are found as well as a number of other resonancelike features