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Eine regelmäßige Abhängigkeit der 29Si‐chemischen Verschiebungen von der Anzahl der mit dem untersuchten SiO4‐Tetraeder verknüpften A104‐ Tetraeder erlaubt qualitative und halbquantitative Ausssagen zur Zeolithstruktur, speziell zur Si/Al‐Ordnung im Alumosilicatgitter.

1992 magnetic resonance, nuclear quadrupole resonance magnetic resonance, nuclear quadrupole resonance (solids and liquids) D 6560 -011Crystallographic Site Discrimination in Aluminophosphate Molecular Sieves by Solid-State NMR: Influence of the Field-Dependent Isotropic Second-Order Quadrupolar Shift on High-Resolution 27Al DOR NMR. -The low-field 27Al double-rotation NMR results obtained for the very large pore aluminophosphate VPI-5 confirm the recently reported crystal structure refinement (based on a symmetry reduction from P63cm to P63) and demonstrate the importance of the isotropic second-order quadrupolar shift for crystallographic site discrimination. -(GROBET, P. J.; SAMOSON, A.; GEERTS, H.; MARTENS, J. A.; JACOBS, P. A.; J. Phys. Chem. 95 (1991) 24, 9620-9622; Cent. Oppervlaktechem. Katal., Kathol. Univ. Leuven, B-3001 Heverlee, Belg.; EN)