Resolving crystallographically nonequivalent tetrahedral sites

A few cases have come to light in which crystallographic nonequivalence of tetrahedral sites for silicon has been reflected in the 29Si MAS NMR spectra of zeolites. The most complex and the best resolved example is the spectrum of silicalite which was discussed in Section III,F another is the spectrum of the well-ordered natural zeolite scolecite (57), which contains two signals corresponding to nonequivalent Si(3 Al) units (see Fig. 23). The correctness of... 

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