Finally, we examine the absorption spectrum of the hydrated electron, which has frequently been used to interrogate structural models of this unusual species, often using TD-DFT calculations. For this purpose we selected three well-spaced snapshots from a QM/ MM simulation, with DFT regions extending to a radius of 7.5 Å and consisting of (H 2 O) - N with N = 68-71. Tuning was performed separately for each snapshot and the results are quite consistent across structures, with ω GDD = 0.248-0.253 bohr -1 and ω IE = 0.150-0.155 bohr -1 .