The spectrum resulting from cavity-like final states (identified by S > 0.67) is shown as the grey-filled area in Fig. , confirming that these states dominate the 533 eV feature. The deviation between the theoretical XAS and the cavity contributions at higher energy results largely from changes to the 535 eV pre-edge peak in e - (aq) compared to pure water. The analysis of the pre-edge peak is beyond the scope of this communication, but will be revisited once the experimental path length is reduced, allowing higher excitation energies to be probed experimentally.