experimental 1D spectrum (Fig. ). A wide distribution of CQ values and calculated quadrupolar induced shifts (𝛿 0 % ) across Al sites which ranges from 10 to 20 MHz (Fig. ), with a wider range for both Al(IV) and Al(V) environments. The calculated isotropic shieldings and corresponding quadrupolar shifts show similar trends to experiment, indicating that the model captures these features from NMR. The spin-simulation tool SIMPSON was used to incorporate quadrupolar interactions at three fields (11.75 T, 16.44 T, 23.49 T) corresponding to the three fields at which the experimental NMR spectra (Fig. ) were obtained. The resulting spectra are shown in Fig. and the quadrupolar nature of the Al(IV) and Al(V) environments is well described as evidenced by the sloping tails towards lower 𝛿 !"# values, which are indicators of quadrupolar environments. Furthermore, trends at increasing field strengths are captured by both theory and experiment, with higher fields showing sharper peaks of the Al(IV,V,VI) environments, and a narrower overall spectral width.