  The ionization potential distributions of hydrated hydroxide and hydronium
are computed with many-body approach for electron excitations with
configurations generated by {\it ab initio} molecular dynamics. The
experimental features are well reproduced and found to be closely related to
the molecular excitations. In the stable configurations, the ionization
potential is mainly perturbed by water molecules within the first solvation
shell. On the other hand, electron excitation is delocalized on both proton
receiving and donating complex during proton transfer, which shifts the
excitation energies and broadens the spectra for both hydrated ions.
