However, interpreting NMR spectra for complex zeolite structures, such as H-ZSM-5, is challenging due to signal overlap and the quadrupolar nature of the 27 Al nucleus. In particular, the chemical shift region between 53 and 56 ppm is expected to represent signals from 16 different T-sites (see Fig. ), and considering that the Al nucleus causes broadening of spectral peaks with line widths ranging from 0.9 to 2.3 ppm at 14.1 T, it is easy to see that this will significantly complicate the assignment of experimental NMR signals. Nevertheless, as an example, we attempted to calculate the complete NMR spectra going beyond isotropic chemical shifts including the quadrupolar broadening testing various reasonable simplified estimates of the C Q parameter, obtaining, as expected, a range of sizably different NMR spectra (see Section S12 in ESI † for details) exemplifying the problems with the reliable signal assignment. Moreover, these difficulties are further exacerbated when cations are attached to the zeolite framework, as they can further broaden the NMR signals. To mitigate this, NMR measurements are typically conducted on fully hydrated zeolites, where the presence of water leads to narrower peaks. Note, however, that recent studies have begun incorporating additional parameters, such as chemical shift anisotropy to distinguish overlapping signals more effectively. Similarly, a few recent computational studies have proposed machine learning models capable of predicting full NMR shielding and EFG tensors. A combination of these approaches holds promise to overcome the challenges in assignment and interpretation of the Al NMR spectra.