NIST Crystal Data File

Currently, there are about 197,500 entries in the National Institute of Standards and Technology (NIST) Crystal Data File. An exhaustive search takes about one minute. Unit cell parameters are very definitive. Usually only one or a few hits are found and the appropriate Hterature reference(s) are Hsted. If no hits are found, the stmcture has not been previously reported. 

Indexings and Lattice Parameter Determination. From a powder pattern of a single component it is possible to determine the indices of many reflections. From this information and the 20-values for the reflections, it is possible to determine the unit cell parameters. As with single crystals this information can then be used to identify the material by searching the NIST Crystal Data File (see "SmaU Molecule Single Stmcture Determination" above). 

NIST Crystal Data File International Centre for Diffraction Data 1601 Park Lane... 

International Centre for Diffraction Data — Maintains and distributes the Powder Diffraction File (PDF), a file of over 500,000 X-ray powder diffraction patterns used for identification of crystalline materials. The ICDD also distributes the NIST Crystal Data file, which contains lattice parameters for over 235,000 inorganic, organic, metal, and mineral crystalline materials. Address 12 Campus Blvd., Newton Square, PA 19073-3273 [www.icdd.com]. 

Technology (NIST), 15 762-763, 767 19 588 24 436. See also NIST Advanced Technology Program buffer solution standards, 14 25, 26 Crystal Data File, 26 424 standards, 15 742... 

The databases PDF (Powder Diffraction File) and NIST Crystal Data must, at least, be mentioned. They do not contain primary data but they are important tools for analytical purposes in the solid state. 

The Powder Diffraction File is maintained by ICDD - International Centre for Diffraction Data httD //www.icdd.com. The Inorganic Crystal Structure Database is produced by the Fachinforrnationszentnrm Karlsnrhe (FIZ) httD //www.fiz-karlsruhe.de/and the National Institute of Standards and Technology (NIST) httD //www.nist.gov/srd/nist84.htm Shirley, R., Acctuacy in Powder Diffraction. In NBS Spec. Publ., Block, S. H., C.R., Ed. 1980 Vol. 567, pp 361-382. 

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