at the FlexiBLE QM/MM level (solid black curve) are dominated by two features: a broad peak centered at 3530 cm -1 , and a pair of peaks at 1500 and 1750 cm -1 . The 3530 cm -1 peak is assigned to water's OH stretch, while the 1750 cm -1 peak corresponds to water's bend. These numbers are somewhat higher than the experimental e - (aq) RR peak frequencies of 1610 and ∼3200 cm -1 ; 72 however, applying the recommended vibrational frequency scaling factor of 0.9374 for BH&HLYP brings the theoretical frequencies into better agreement with experiment. We will address the 1500 cm -1 peak further below.