Photo double detachment of CN$^{-}$: Electronic decay from an inner-valence hole in molecular anions

The first measurements of inner-valence photodetachment from CN$^{-}$ as well as theoretical calculations around the 2-electron threshold (25--90 eV) will be presented. Measured absolute cross sections for CN$^{+}$ production by photo double detachment of CN$^{-}$, and for C$^{+}$ and N$^{+}$ fragments produced from the dissociation of the excited molecule will be reported. The measurements also reveal the signature of inner-valence autoionization, similar to the interatomic Coulombic decay (ICD) phenomenon. This work confirms the predicted effect, which should in general be present for molecular anions, even in very small molecules.