International Centre for Diffraction

Powder Diffraction File, Pub. SMA-29, JCPDS, International Centre for Diffraction Data, Swarthmore, Pa., 1979. 

JCPDS-ICDD Elemental and Lattice Spacing Index ilDDO). This index is available from JCPDS-International Centre for Diffraction Data, 1601 Park Lane Swarthmore, PA 19081. 

ICDD PDF-2 Database, International centre for diffraction data. 

The International Centre for Diffraction Data (ICDD, Newtown Square, Pa.) maintains a collection of single-phase x-ray powder patterns [5]. There are separate listings of inorganic and organic compounds. The x-ray diffraction data of ibuprofen, as a representative example, is given here (Fig. 1). 

Recent developments and prospects of these methods have been discussed in a chapter by Schneider et al. (2001). It was underlined that these methods are widely applied for the characterization of crystalline materials (phase identification, quantitative analysis, determination of structure imperfections, crystal structure determination and analysis of 3D microstructural properties). Phase identification was traditionally based on a comparison of observed data with interplanar spacings and relative intensities (d and T) listed for crystalline materials. More recent search-match procedures, based on digitized patterns, and Powder Diffraction File (International Centre for Diffraction Data, USA.) containing powder data for hundreds of thousands substances may result in a fast efficient qualitative analysis. The determination of the amounts of different phases present in a multi-component sample (quantitative analysis) is based on the so-called Rietveld method. Procedures for pattern indexing, structure solution and refinement of structure model are based on the same method. 

Aust. J. Soil Res. 16 215-227 Joint Committee on Powder Diffraction Standards Mineral powder diffraction fde. Data book. Published by the JCPDS International Centre for Diffraction Data, Swarfhmore, Pennsylvania, U SA, pp. 942 Jolivet, J.P. Tronc, E. (1988) Interfadal electron transfer in colloidal spinel iron oxide. Conversion of Fe304 to y- Fe203 in aqueous medium. J. Colloid Interface Sci. 125 688—... 

McClune, W.F., editor-in-chief, Powder Diffraction File, JCPDS-International Centre for Diffraction Data, Swarth-more, PA. 

Most biomolecules, such as polysaccharides, simple sugars, lipids, and proteins, are crystalline (International Centre for Diffraction Data, 2006). If HS consist merely of associations of biological residues, they should have characteristic crystal structures that can be rigorously studied and identified by X-ray diffraction analysis. However, the research evidence clearly shows that environmental organic matter has to be considered as highly amorphous material, which additionally contains microcrystalline regions like polymethylene crystallite (Hu et al., 2000 Schaumann, 2006b). 

International Centre for Diffraction Data (ICDD) (2006). Powder diffraction file Organic and organometallic phases search manual for experimental patterns. International Centre for Diffraction Data, Newton Square, PA. 

ICDD International Centre for Diffraction vuv vacuum ultraviolet... 

X-ray powder diffraction files (PDFs) for explosive materials are available as subsets of PDF libraries, such as Xpowder and that of the International Centre for Diffraction Data (ICDD). Commercial X-ray diffractometers can yield lattice spacings, d, to a precision of 0.0001 A. At this accuracy, it is not difficult to distinguish uniquely between many thousands of chemical compounds. Hence, XRD is a standard analytical technique for precisely identifying crystalline materials. 

ICDD, International Centre for Diffraction Data, Powder Diffraction File—2 Sets 1 7, Card iS-ii 7 (1997a). 

The immense number of chemical compounds formed by the halogens provides chemists with an extraordinary database from which numerous chemical and physical phenomena can be correlated with respect to various periodic trends. From databases like Inorganic Crystal Structure Data (ICSD, http //www.fiz-karlsruhe.de ) and International Centre for Diffraction Data (ICDD, http //www.icdd.com) with 67 000 and 25 000 entries, respectively, one can easily make out that halides are one of the dominant classes of compounds besides oxides. Even within the subset of inorganic solids, there is tremendous diversity of composition, stracture, and properties and to summarize this would create its own encyclopedia. Therefore, the discussion in this article is limited primarily to binary halides, their structures, and some of their properties, except halides of elements which are nonmetals. Binary actinide hahdes are discnssed elsewhere see Actinides Inorganic Coordination Chemistry). Complex hahdes (sohd phases containing two or more kinds of metal ions), ... 

The simplest application of powder diffraction is to identify a crystalline phase. One merely runs the powder pattern of the solid and records either 29 values or rf-spacings or both. This information is given by the program and can be printed directly on the pattern. Then one may consult a database such as the JCPDS file. These initials refer to the JCPDS. As a result of the complexity of keeping pace with the ever growing fist of known phases, the operation grew and was renamed the International Centre for Diffraction Data (ICDD), headquartered in Newton Square, Pennsylvania. 

Data collection software is generally supplied by the instrument manufacturers. This data collection software would also normally be equipped to perform preliminary analysis including peak finding routines and search/match of powder diffraction patterns from a database. The most popular database for powder diffraction data is maintained by the International Centre for Diffraction Data. ... 

ICDD, Powder Dijfraction File, ed. W. F. McClune (Newton Square, PA International Centre for Diffraction Data, 2000). CIF from library of crystal files in Centre for Innovation Enterprise, CrystalMaker Software Limited (Oxford Oxford University, 2006). See example in Section 14.7. 

Access to powder patterns generated from single crystal structures has been considerably faciUtated by a cooperative arrangement between the Cambridge Crystallogr hic Data Centre (die repository of die experimental crystal structure data) and the International Centre for Diffraction Data (the repository for powder diffraction data). Eidier one of these organizations may be contacted for furdier details. 

Mighell, A. D. and Stalick, J. K. (1983). Crystal data. Determinative tables. Vol. 6, 3rd edn. U. S. National Institute of Science and Technology, JCPDS—Joint Committee on Powder Diffraction Standards, ICDD—International Centre for Diffraction Data. [14]... 

Newman, A. W., Stephens, R W., Morrison, H. G, Andres, M. C., Shatly, G. P. and Thomas, A. S. (1999). Quantitation of two polymorphic forms using Rietveld analysis, synchrotron XPRD and traditional XPRD. Presentation notes, pp. 85-96. Pharmaceutical Powder X-ray Diffraction Symposium, organized by International Centre for Diffraction Data, 27-30 Sep., 1999. [122, 123f, 124f]... 

International Centre for Diffraction Data 1601 Park Lane... 

FIGURE 16.5. Data for two salts from the Powder Diffraction File. The crystal system, unit-cel] dimensions, space group and bibliographic references are given together with experimental details. Listed on the tight ate dhki, I hkl) and hkl for the most intense Bragg reflections. Courtesy, JCPDS — International Centre for Diffraction Data (ICDD), publishers of the Powder Diffraction File. 

This chapter presents an overview of the crystal structures of inorganic compounds in which actinide polyhedra are directly coordinated by phosphate or arsenate tetrahedra. Arsenates are considered here for comparative purposes, because of the very similar structural roles played by arsenate and phosphate ions. Structural data are taken mainly from the Inorganic Crystal Stmcture Database [6] and the published literature. Entries from the Powder Dififtaction File of the International Centre for Diffraction Data [7] have been consulted in the case of compounds whose structures may reasonably be inferred. Mixed organic-inorganic compounds [8] and polyoxometalates are not addressed phosphites, phosphinates and arsenites also fall outside the scope of this chapter. Data are tabulated for a given structure type, with phosphates separated... 

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