International Centre for Diffraction Data 1517848 178957358 2007-12-19T14:52:05Z Tone 266534 {{Physics-org-stub}} The '''International Centre for Diffraction Data''' ('''ICDD''') maintains a database of [[powder diffraction]] patterns, the '''Powder Diffraction File''' (PDF), including the d-spacings (related to angle of diffraction) and relative [[intensity (physics)|intensities]] of observable [[diffraction]] peaks. Patterns may be experimentally determined, or computed based on [[crystallography|crystal structure]] and [[Bragg's law]]. It is most often used to identify substances based on [[x-ray diffraction]] data, and is designed for use with a [[diffractometer]]. The database is exhaustive, over 500,000 entries as of [[2006]]; computer algorithms allow rapid peak matching. The organization was founded in 1941 as the '''Joint Committee on Powder Diffraction Standards''' ('''JCPDS'''). In 1978, the name of the organization was changed to the current name to highlight the global commitment of this scientific endeavor. The International Centre for Diffraction Data (ICDD) is a nonprofit scientific organization, founded by, and dedicated to scientists working in the field of X-ray analysis and materials characterization. The ICDD produces materials databases, characterization tools, and educational materials, as well as organizing and supporting global workshops, clinics and conferences. It provides the scientific community with the tools required for X-ray analysis while continuing to educate and inform current and future scientists in the field. Products and services of the ICDD include the Powder Diffraction File databases, educational workshops, clinics and symposia as well as sponsorship of the Denver X-ray Conference. The ICDD also publishes the journals ''Advances in X-ray Analysis'' and ''Powder Diffraction''. As mentioned above, the Powder Diffraction File contains powder diffraction data and is designed to work with a diffractometer to identify unknown materials. With every entry, the database also contains bibliographic references, chemistry descriptions, structural classifications, crystallographic and physical properties. ==See also== *[[powder diffraction]] *[[crystallography]] ==External links== * [http://www.icdd.com/products/ICDD.PDF History, contents & use of the PDF] Information about the ICDD, its products and services, can be found at www.icdd.com. * [http://www.icdd.com International Centre for Diffraction Data] Technical articles on x-ray methods and analyses * [http://www.icdd.com/resources/axasearch/AXA_login.php Advances in X-ray Analysis] [[Category:Crystallography]] [[Category:Diffraction]] [[Category:Optics institutions]] {{Physics-org-stub}}