Oscillations in the n-body interactions are quite small for the charge-neutral water clusters, albeit still largest with the PBE functional. These oscillations are reduced in magnitude, though not eliminated, by the hybrid functionals. A previous study of hydrated ions using SIEcorrected functionals concluded that SIE is important in although the systems examined were limited to N ≤ 2. For Na + (H 2 O) 14 , we find that MBE(n) diverges using any of the aforementioned functionals except for HF. These exaggerated many-body effects are much larger than what is observed at the three-body level for Na even with semilocal functionals. This difference between microhydrated systems considered in previous studies, and the full solvation-shell clusters examined here, may explain why problems with DFT-based MBE(n) calculations have not been reported previously.