Å, compared to about 6.0 Å in IFR and 7.2 Å in STT. The average F-N distance is significantly lower than in the previously studied MFI-type system containing MTBA + cations, where the attraction between the positively polarized part of the OSDA and the fluoride anions is strong enough to suppress the dynamic disorder at 298 K. In the light of this, it seems reasonable to conclude that F-OSDA interactions are also responsible for the absence of dynamic disorder in CHA. From a more general point of view, local interactions within the cage determine whether a dynamic motion of fluoride anions between different sites can occur at all, but attractive interactions with the OSDA cations may suppress it in systems where it should be possible according to the local geometry. Additionally, the discrepancy between the pronounced dynamic disorder in IFR and the large value of ΔErel of the F@Si6_2 site is worth a more detailed analysis. As the two Si atoms have an equivalent environment when only the framework is considered, the large difference in energy must stem from interactions with the OSDA, and the above analysis identified the shorter distance between the fluoride anion and the O atom of the BQol + OSDA as the reason why F@Si6_2 is energetically less favorable (Figure ). There are two possible explanations why this large energy difference does not prevent the dynamic motion between the F@Si6_1 and F@Si6_2 sites: Firstly, the thermal motion of the OBQol atoms could lead to an increase of the overall average F-OBQol distance, reducing the energy difference between the two fluoride locations. Alternatively, fluoride anions and OBQol atoms might move in a concerted fashion, so that the hopping of a fluoride anion would coincide with a change of position of the closest OBQol atom. In this context, it is worth noting that the displacement ellipsoid of the OBQol atoms in the experimental structure is large and highly anisotropic, with the longest axis of the displacement lying roughly parallel to the a axis (Figure ). This indicates significant thermal oscillations of these atoms, but provides no evidence for a correlation with the dynamic disorder of the fluoride anions, which are displaced along b (Figure ). Further evidence for the first of the above hypotheses can be obtained from the AIMD results: The F-OBQol RDF, shown for all three temperatures in Figure (Supporting Information), exhibits a relatively broad first maximum centred at about 6.3 Å. As becomes clear from the plot of the cumulative g(r), this maximum includes contacts to the nearest and second-nearest OBQol atom. The cumulative g(r) for 298 K reaches a value of 0.5 at a distance of about 5.96 Å. In other words, F-OBQol contacts shorter than this distance occur only during 50% of the total simulation time. Compared to the distances in the DFT-optimized structures (5.80 Å for F@Si6_1, 5.45 Å for F@Si6_2), this is a significant shift towards a larger average F-OBQol separation, which would weaken the electrostatic repulsion and facilitate hopping events between the two F@Si6 positions. The second hypothesis of a concerted hopping can be ruled out by plotting the y coordinates of adjacent F and OBQol atoms together. This has been done exemplarily for three F-OBqol pairs in Figure . In all three plots, the hopping of fluoride anions is clearly visible as a discontinuous change in y coordinate, whereas the OBQol atoms show only random oscillations. It can thus be concluded that the dynamic disorder of the fluoride anions is not coupled to, let alone triggered by, displacements of the closest OBQol atoms.