To complement crystallographic investigations, a few authors have employed computational methods to compare different possible fluoride locations within a given zeolite: In particular, Pulido et al. carried out force-field based calculations to study the fluoride positions in all-silica zeolites with the IFR, ITH, IWR, STF, and STT topologies. For those systems where experimental information was available, they observed good agreement between the computationally predicted sites and the experimental fluoride positions (as a caveat, it has to be noted that they reported their energies with a precision of only 0.1 eV = 9.6 kJ mol , often leading to several sites having the same energy). With regard to a more general understanding of preferred fluoride sites, this comparative study yielded the following key results: In the first place, electrostatic interactions between fluoride anions and OSDA cations determine in which of the available cages the fluoride anions are incorporated. Second, the specific position within the cage is governed by localized F-Si interactions. More recently, Luo et al. employed dispersion-corrected DFT calculations to predict the energetically preferred fluoride sites in an MWW-type all-silica zeolite. They obtained very similar energies for two fluoride locations in different cages, concluding that the coexistence of two fluoride environments is responsible for the presence of two distinct resonances in the F NMR spectrum.