@article {4828,
	title = {Lattice energy-minimization calculation in the further investigation of XRD and NMR studies of zeolite frameworks},
	journal = {Chemistry of Materials},
	volume = {12},
	number = {2},
	year = {2000},
	note = {ISI Document Delivery No.: 287JNTimes Cited: 6Cited Reference Count: 29},
	month = {Feb},
	pages = {336-342},
	type = {Article},
	abstract = {A knowledge of the local structure of zeolite frameworks is an important prerequisite for a detailed and quantitative understanding of e.g, catalytic processes. In the present work the sensitivity of 1D and 2D MAS NMR experiments to the local order of framework T atoms and energy-minimization calculations for the geometrical analysis of the complete zeolite framework structure are combined to provide a most detailed view of their structural properties. Correlations of the chemical shifts, delta(Si-29), with the mean distance between Si and its neighboring Si T atoms, (d) over bar(Si-Si), are presented for the three materials MFI, MEL, and MTT. Excellent agreement between experimental and computational results was obtained. In the case of MFI, this most complicated structure was used to demonstrate the viability of the method. The MTT and MEL systems showed that it is possible to deduce the unique assignment of the NMR spectra from energy-minimized structures when it is not possible using the available structural data from X-ray structure analysis. Taken together, all three investigations also demonstrate that improved structural data are obtained from lattice energy minimizations compared to those from Rietveld analysis as long as the topology of the framework is known.},
	keywords = {3-DIMENSIONAL BONDING CONNECTIVITIES, CHEMICAL-SHIFTS, HIGH-TEMPERATURE, NUCLEAR MAGNETIC-RESONANCE, ORTHORHOMBIC FRAMEWORK, SI-29 MAS-NMR, SILICA POLYMORPHS, SOLID-STATE NMR, X-RAY-DIFFRACTION, ZSM-11},
	isbn = {0897-4756},
	url = {<Go to ISI>://000085502900017},
	author = {Hochgrafe, M. and Gies, H. and Fyfe, C. A. and Feng, Y. and Grondey, H.}
}
@inbook {3404,
	title = {Powder x-ray diffraction and solid state NMR techniques for zeolite structure determination},
	booktitle = {Catalysis by Microporous Materials},
	series = {Studies in Surface Science and Catalysis},
	volume = {94},
	year = {1995},
	note = {ISI Document Delivery No.: BE31JTimes Cited: 4Cited Reference Count: 33Proceedings PaperInternational Symposium on Catalysis by Microporous Materials (ZEOCAT 95)JUL 09-13, 1995SZOMBATHELY, HUNGARYSARA BURGERHARTSTRAAT 25, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS},
	pages = {78-100},
	publisher = {Elsevier Science Publ B V},
	organization = {Elsevier Science Publ B V},
	address = {Amsterdam},
	abstract = {The synthesis of zeolites, porous aluminosilicates, had a large impact on the development of catalyst materials. The framework structures of these systems consist of Si and Al atoms, referred to as T-atoms, tetrahedrally coordinated to oxygen atoms to form topologies with well defined and regular channel systems. Cations are necessary to satisfy the charge on the Al atoms and are exchangeable. The T-atoms may also consist of any atom capable of isomorphorus substitutions for Si. Since good quality large zeolite crystals are not available, powder X-ray diffraction is used to derive structural information, and with improvements in powder diffraction instrumentation and the availability of synchrotron and rotating anode high intensity Xray sources, much higher quality structure data is obtained. The combined application of solid state NMR which probes short-range order, X-ray diffraction which is a long-range order technique and Rietveld refinement has greatly increased both the quantity and quality of structural information available.},
	keywords = {aluminum, COMBINATION, SI-29, ZSM-11},
	isbn = {0-444-82049-3},
	url = {<Go to ISI>://A1995BE31J00009},
	author = {Kokotailo, G. T. and Fyfe, C. A. and Feng, Y. and Grondey, H. and Gies, H. and Marler, B. and Cox, D. E.},
	editor = {Beyer, H. K. and Karge, H. G. and Kiricsi, I. and Nagy, J. B.}
}
@article {7023,
	title = {THE COMBINATION OF SYNCHROTRON POWDER DIFFRACTION AND HIGH-RESOLUTION SOLID-STATE NMR EXPERIMENTS},
	journal = {Journal of Physics and Chemistry of Solids},
	volume = {52},
	number = {10},
	year = {1991},
	note = {ISI Document Delivery No.: GU763Times Cited: 18Cited Reference Count: 22},
	pages = {1235-1241},
	type = {Article},
	abstract = {Structural investigations on three zeolites, ZSM-11, ZSM-12 and ZSM-5, have been carried out by a combination of high-resolution solid-state Si-28 NMR experiments and Rietveld refinement of synchrotron X-ray powder data. These techniques, being sensitive to short- and long-range order, respectively, gave a most complete picture of the structure of the solid state. Variable temperature NMR experiments of ZSM-11 revealed a displacive phase transition with a change in symmetry at about 300 K. A Rietveld refinement of a data set recorded at 373 K confirmed the proposed structure model. The structure of ZSM-12 was refined from room temperature synchrotron powder data. Space group ambiguities because of pseudo-symmetry of the silica framework of the zeolite were resolved with the aid of Si-29 NMR experiments leading to C2/c as the true space group symmetry. Si-29 NMR and X-ray studies of ZSM-5 showed that the symmetry of the crystal structure depends on the temperature, the concentration of the guest molecule, and on the number of Al atoms in the framework. A full pattern refinement of silica-ZSM-5 loaded with two molecules p-dichlorobenzene per unit cell showed that the site occupied by the sorbed molecule is not at the intersection of the channels but shifted by 1/4 along b0.},
	keywords = {3-DIMENSIONAL LATTICE CONNECTIVITIES, CRYSTAL-STRUCTURE, ORTHORHOMBIC FRAMEWORK, Rietveld refinement, Si-29 NMR, SINGLE-CRYSTAL, SORBATE, ZEOLITE H-ZSM-5, zeolites, ZSM-11, ZSM-12, ZSM-5},
	isbn = {0022-3697},
	url = {<Go to ISI>://A1991GU76300006},
	author = {Gies, H. and Marler, B. and Fyfe, C. and Kokotailo, G. and Feng, Y. and Cox, D. E.}
}
