The NMR isotropic shieldings for all 2160 atoms in the amorphous model are calculated using DFT GIPAW NMR and reproduce the total isotropic range and location of shifts in the The distributions of Al environments are shown and broadening of 8 ppm is applied to the total NMR spectrum. Note that this x-axis is 𝛿 !"# indicating that this is a plot of the isotropic shifts from each individual Al atom, rather than the quadrupolar lineshapes (shown in Fig. ). This corresponds to the spectrum at an infinitely high magnetic field. (D) Comparison of 𝛿 !"# and 𝛿 $" from GIPAW NMR where the second-order quadrupolar shift (𝛿 $" ) is calculated using the method from . This method again shows distortions in the quadrupolar dimension for both Al(IV) and Al(V), which is consistent with the MQMAS in B. The distribution of 𝛿 $" indicates that quadrupolar effects play a large role in the experimental 1D lineshape.