The electronic exchange-correlation functional can have a considerable influence on molecular vibrational frequencies. In previous work, , several exchange-correlation functionals, including B3LYP, 37,41 PBE0, 42 and ωB97X, has been tested against the results from the gold standard CCSD(T) method. For PTMs in H 5 O 2 + and H 3 O 2 -, the ωB97X functional, when combined with the aug-cc-pVDZ basis set, was found to provide the best agreement with CCSD(T) results with a large basis set. Because of the large computational cost of CCSD(T), it is impractical to benchmark large shared proton systems; therefore, in this work, we continue to use the ωB97X functional as the electronic exchange-correlation functional for calculations. Unless specified otherwise, the aug-cc-pVDZ basis set was employed for electrons.