Gismondine-type framework

W. M. Meier (Eidgenossische Technische Hochschule, Zurich) The structure of NaPl (Bi) has recently been solved using x-ray intensities obtained from a multiply-twinned crystal in addition to powder data. Refinement proceeded to an intensity R value of 0.077. The structure is based on a gismondine-type framework and is thus noncubic. The maxi-... 

The crystal structure of the synthetic zeolite Na-Pl, represented by the formula NaeAleSiio,12H20, has been solved by X-ray methods. It is closely related to the gismondine-type framework. 

The transformation of NaY into a gismondine-type framework (GIS) or into ZSM-4 (mazzite) (MAZ) is well known [138], Typically, Al-rich zeolites, viz. A and X, yield the dense sodalite structure. When overexposed to the reaction medium. Si-rich zeoKtes are transformed into dense quartz phases, while in... 

The major crystal structures of AlPO-n and AlPO-n-based molecular sieves are summarized in Table 1 At present, there are 31 AlPO-n materials whose crystal structure has been determined. They include 18 novel structures as well as 13 structures with framework topologies related to those found in the zeolites such as chabazite (n=34, 44, 47), erionite (n=17), gismondine (n=43), levynite (n=35), Linde type A (n=42), faujasite (n=37), and sodalite (n=20). Among these, the crystal structure of AlPO-5 has been the most widely studied. Figure 1 shows the pore structure of AlPO-5. The structure of... 

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