It is important to mention that the chloride ion was added to the system merely to create a cavity. During these simulations, the chloride ion was not reactive towards PFOA/PFOS (whereas the hydrated electron is reactive). To compare the degradation dynamics of hydrated electrons against crude configurations using an excess electron, we carried out 25 additional trajectories (13 and 12 trajectories for PFOA and PFOS, respectively) by simply initializing the system with an overall negative charge without preparing a cavity. Additional cavity preparation details are given in the Supporting Information.