The type material of the STF framework type is the zeolite SSZ-35. The crystal structure of assynthesized SSZ-35 was reported by Villaescusa et al. In this monoclinic structure (space group 𝑃2 1 /𝑐), fluoride is disordered over two symmetry-equivalent positions, which are located in adjacent ] cages that are fused together via the 4MR. The OSDA (racemic N,N-dimethyl-6azonia-1,3,3-trimethylbicyclo(3.2.1)-octane) in this structure is heavily disordered, complicating the preparation of a starting model that is suitable for DFT calculations. Similar problems would arise for a triclinic structure (space group 𝑃1 ̅ ) published later by Zones et al. A fully ordered structure was reported by Paillaud et al., who prepared an STF-type all-silica zeolite dubbed Mu-26 using DMASD + cations. In this triclinic structure (space group 𝑃1), only one cage in each pair of fused ] cages contains fluoride anions, which are bonded to the Si3 atoms (Figure ).