The Diazene Cation

From the photoelectron spectrum (PES) of gaseous trans-N2H2 and trans-N2D2 [10, 11], the following term energies Tq and vibrational frequencies v for various electronic states 

The geometry of the ground-state ion was deduced from the vibrational structure of the corresponding band in the PES. Compared to the neutral species, the angle is widened  

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