To date, all previous theoretical studies on PFAS degradation have used either static vertical/adiabatic density functional theory (DFT) calculations or dynamics calculations with an excess electron/charge to approximate a true hydrated electron. It is important to emphasize that simply introducing an excess electron/charge in a simulation does not accurately mimic a hydrated electron since this additional electron is not polarized by the surrounding water molecules. More importantly, this excess charge (which has been commonly used in theoretical calculations up to this point) does not directly capture the realistic configuration of a hydrated electron used in experimental studies. For example, excess electrons can be experimentally produced in neutral water via radiolysis or instantaneous ionization/detachment of other solutes; however, these processes do not yield hydrated electrons that are polarized by the surrounding water molecules. It is only when these electrons have lost sufficient energy to become metastable localized species bound by water that they can be designated as hydrated electrons. It is the latter configuration that we examine with advanced ab initio molecular dynamics (AIMD) to understand these important PFAS degradation mechanisms for the first time.