Introducing an additional aluminium (and proton) into the zeolite unit cell perturbs the original isolated aluminium environment and thus also the 27 Al chemical shifts. This effect is typically disregarded in computational studies as it introduces a combinatorial increase in the number of possible configurations, making it challenging to treat extensively and comprehensively at the ab initio level. The extent of this perturbation/interaction was shown to correlate very weakly with the distance between aluminium atoms by a previous study, which aligns with our findings below and suggests a more complex underlying dependence.