We first consider a data set consisting of ten F -(H 2 O) 15 clusters, with calculations performed using either the PBE functional or else Hartree-Fock (HF) theory. We examine basis sets aug-cc-pVXZ (abbreviated "aXZ") for X = D, T, and Q. Errors in MBE(n) ap-proximations up to n = 6 are plotted in Fig. . Ratios of the MBE(n) approximation, ∆E int [MBE(n)], to the CP-corrected supramolecular result (∆E int ) are plotted in Fig. . (Analogous ratios are provided in the Electronic Supplementary Information for other error plots provided in this work.)