“…New NMR techniques, e.g., dynamic angle spinning (DAS) [3,4], double rotation (DOR) [5], and multiple-quantum excitation in combination with fast spinning (MQMAS) [6], were recently developed for quadrupole nuclei with half-integer spins, and, in addition, the perturbing effect of the electric quadrupole interaction is reduced at the higher magnetic fields, which are now available. Numerous 17 O NMR investigations applying these techniques were performed, in order to correlate the obtained NMR parameters of resolved oxygen signals with structure data obtained by diffraction methods: Grandinetti et al [7] investigated the SiO 2 polymorph coesite, Mueller et al [8] measured the 17 O signals of diopside, forsterite, clinoenstatite, wollastonite, and larnite by DAS NMR, and Bull et al [9,10] investigated the silicon-rich zeolites Sil-Y and ferrierite by 17 O DOR NMR. We investigated several hydrated zeolites by 17 O 3Q MAS and DOR NMR and demonstrated the reasonably good resolution in the field of 17.6 T, whereas we obtained nonsufficient resolution in the lower field of 11.7 T [11,12].…”