Structure determination using high-resolution powder

Fagan, P. G., Roberts, K. J., Docherty, R., Chorlton, A. R, Jones, W., and Potts, G. R, An ab-initio approach to crystal structure determination using high-resolution powder diffraction and computational chemistry techniques application to 6,13-dichlorotriphendioxazine, Chem. Mater., 7, 2322, 1995. 

Determining the Structure of Molecular Sieve Materials Using High-Resolution Powder Data... 

Zeolitic materials have been prominent amongst those so far studied by high resolution powder diffraction using synchrotron X-rays [36]. High definition synchrotron PXD data has been helpful in a number of framework structure determinations and has facilitated studies of planar faulting (see below). Successful Rietveld refinements of the framework structures of zeolite ZSM-11 [37, 38] and silica-ZSM-12 [39], and of the complete structures of zeolite Y containing cadmium sulfide [40] and cadmium selenide [41] clusters have been described. 

Hammond, R. B., Roberts, K. J., Docherty, R., Edmondson, M., and Gaims, R., X-form metal free phthalocyanine Crystal structure determination using a combination of high resolution X-ray powder diffraction and molecular modelling techniques, J. Chem. Soc. Perkin Trans., 2, 1527, 1996. 

X-ray, neutron, and electron diffraction techniques are used to determine crystal structures and can thus be used for molecular structure determinations. Because of its high resolution and applicability to small and often weakly diffracting samples, x-ray crystallography and powder diffraction are by far the methods of choice for most structure determinations on crystalline compounds,... 

Such a refinement program was very useful in these cases but is in general of limited application, for it is only with very simple structures (both nuclear and magnetic) that a sufficient number of nuclear intensities can be accurately resolved at 4.2K to provide a basis for refinement and the determination of the scale factor. A more general refinement procedure has been recently introduced (69) which fits the measured profile of the powder diffraction pattern rather than individual intensities or structure factors. With data of high resolution obtained over a wide... 

In the field of powder diffraction related to the retrieval of the defects and microstructural information the requirements for using physically meaningful instrumental profile are greater than in the field related to the crystal structural analysis. Thus the following main methods are used. (1) The use of a special high-resolution diffractometer. (2) Experimental determination of the instrumental function for the same material but without defects. (3) Numerical calculations of the instrumental function with ray-tracing simulations. 

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