Having identified the interactions with surrounding Si atoms as an important factor determining the occurrence of dynamic disorder, it is insightful to include the previously studied Silicalite-1 in the analysis. The F•••Si distances in the DFT-optimized structure of MFI containing TPA + cations and fluoride anions are also given in Table . As in IFR and STT, there are two relatively short contacts < 2.8 Å. Dynamic disorder consisting of jumps between the F@Si9_1 and F@Si9_2 sites occurs in this system, corroborating the link between dynamic disorder and interactions with second-and third-nearest neighboring Si atoms. On the other hand, the pronounced variation of the dynamic disorder in MFI depending on the OSDA cannot be understood from these considerations, which take only the local environment into account. Furthermore, if local interactions were the sole determining factor, one would have to expect a similar extent of dynamic disorder in IFR and CHA due to the similar F•••Si distances. The rather different behaviour of these systems shows that other factors, specifically interactions with the OSDA, cannot be disregarded.