Inner-valence ionization of molecular anions and ultrafast relaxation by electron emission

Relaxation mechanisms following inner-valence ionization of CN− are investigated using ab initio quantum chemistry methods. Due to a severe failure of the molecular orbital picture, there is a relatively large number of electronic states that are excited by ionization in the inner-valence regime. Most of these states are found to decay by electron emission, resulting in the formation of vibrationally bound CN+. General conclusions can be drawn concerning larger molecular anions.