Throughout this work, labels including both framework composition and OSDA are used to distinguish different systems (e.g., SiO2-AST_TMA = all-silica AST incorporating TMA cations; as fluoride anions are present in all models, they are not included in the label). The starting models of the framework structure of SiO2-, GeO2-, and AlPO4-AST were taken from experimental crystal structure data. Since GaPO4-AST has, to the authors' knowledge, not yet been synthesised, this model was constructed on the basis of AlPO4-AST. In all starting structures, the fluoride anions were located at the centre of the d4r cages. The cationic OSDAs in the larger ast cages are disordered in the experimental structures. As this disorder had to be removed prior to the DFT calculations, some assumptions regarding the orientation of OSDAs in adjacent cages with respect to each other were necessary. The TMA cation has no dipole moment, so it seems plausible to assume that the orientation of a cation in one cage does not have a strong influence on cations in other cages. Therefore, it was assumed that all TMA molecules have the same orientation, preserving the body-centering of the structure and leading to 𝐼4 ̅ symmetry (Figure ). The situation is different for the QNU cation, which has a dipole moment. An essentially random orientation of the QNU molecules would require the use of a large supercell, and an identical orientation of all molecules (which would preserve the body-centering) would lead to an overall polarisation, which appears unlikely. In order to avoid both issues, an arrangement was used in which all QNU molecules in one plane perpendicular to the c axis (around z = 0) point in one direction, whereas those in the other plane (around z = 0.5) point in the opposite direction (Figure ).