The hydration cluster calculations were performed using Gaussian16 87 using the B3LYP functional and the aug-pcSseg-2 51 and 6-311+G(d,p) basis sets. Starting structures were generated in Avogadro in line with clusters previously presented in the literature. Structures were initially optimised with the 6-311+G(d,p) basis set and NMR parameters calculated. The optimised structures were then reoptimised in the more computationally expensive (and more accurate with respect to NMR chemical shielding) aug-pcSseg-2 basis set. Structures that were below 2.6 kJmol -1 (= kT at T = 308 K, as chosen to be representative of room temperature plus an approximated 10 • C of MAS frictional heating) in energy relative to the ground-state (in either basis-set) were included in NMR parameter maps (Fig. ). A full list of the cluster structures considered with their respective energies are included in Figs. .