It has to be noted that AST-type zeolites and zeotypes are of little relevance for applications because their pores are inaccessible to most guest molecules. However, they constitute an ideal model system in the present context for the following reasons: First, AST-type materials have been synthesised in SiO2, GeO2, and AlPO4 composition, so only GaPO4-AST is a purely hypothetical system. Second, prior experimental studies have shown that each of the larger octadecahedral (ast) cages is occupied by a single OSDA molecule, rather than several molecules. This facilitates the construction of models for the calculations. Given the similarity of the local environment, it can be expected that the findings obtained for AST in the present work are, to a large degree, transferable to other zeolites/zeotypes with d4r cages (probably excepting those where the cages are strongly distorted).