Inner valence levels and Rydberg states of

Inner valence and Rydberg energy levels have been calculated for as a function of internuclear separation. Electron scattering from was solved for negative scattering energies in an R-matrix method which allowed the inclusion of Rydberg states in the configuration interaction calculation. Bound states were found for energies greater than 30 eV which could explain the vibrational-like peaks observed in photoelectron spectra of .