The MDF is used to check data in the Metals section of Structure Reports and to calculate powder patterns for the PDF. It also sends current metal data to Crystal Data. Missing or questionable patterns will be calculated from structural data when available. The system includes routines for calculating interatomic distances, powder patterns, and displaying Frank-Kasper domains, coordination polyhedra, and bonds. Search routines allow finding specific compounds or elements. The file is currently private but a joint program aims to make it publicly available via CISTI. The Protein Data Bank is a computer-based archive for biological macromolecule structures, containing over 100 distinct molecules. Data are distributed from Brookhaven and other centers. Portable programs allow users to extract information. The JCPDS-ICDD publishes the PDF for crystalline phase identification. The PDF is available in various forms, including index cards, microfiche, and books. Subsets include Inorganic and Organic & Organometallic data. Computer search/match procedures and automated diffractometer systems are used for identification. Computer-aided editorial evaluation improves data quality. The NBS AIDS80 program is used to evaluate data entries, including checks for systematic absences, agreement between observed and calculated two-theta, and other tests.The MDF is used to check data in the Metals section of Structure Reports and to calculate powder patterns for the PDF. It also sends current metal data to Crystal Data. Missing or questionable patterns will be calculated from structural data when available. The system includes routines for calculating interatomic distances, powder patterns, and displaying Frank-Kasper domains, coordination polyhedra, and bonds. Search routines allow finding specific compounds or elements. The file is currently private but a joint program aims to make it publicly available via CISTI. The Protein Data Bank is a computer-based archive for biological macromolecule structures, containing over 100 distinct molecules. Data are distributed from Brookhaven and other centers. Portable programs allow users to extract information. The JCPDS-ICDD publishes the PDF for crystalline phase identification. The PDF is available in various forms, including index cards, microfiche, and books. Subsets include Inorganic and Organic & Organometallic data. Computer search/match procedures and automated diffractometer systems are used for identification. Computer-aided editorial evaluation improves data quality. The NBS AIDS80 program is used to evaluate data entries, including checks for systematic absences, agreement between observed and calculated two-theta, and other tests.