The chapter discusses the use of the Metal Data File (MDF) for checking data in Structure Reports and calculating powder patterns for the Powder Data File (PDF) published by the Joint Committee on Powder Diffraction Standards. The PDF is also used to send relevant data on metals to Crystal Data. The MDF includes routines for displaying Frank-Kasper domains, coordination polyhedra, and bonds, as well as search routines for specific compounds. The file is currently available for private use but is being made publicly accessible through the Canada Institute for Scientific and Technical Information (CISTI). The Protein Data Bank (PDB) is introduced as a computer-based archival file for structural data on biological macromolecules, containing atomic coordinates for over 100 distinct molecules, including RNA, DNA, polysaccharides, and proteins. The PDB is distributed upon request from various centers and includes user-friendly computer programs for extracting information. The JCPDS (International Centre for Diffraction Data) is the publisher of the Powder Diffraction File (PDF), which is used for identifying crystalline phases through x-ray powder diffraction patterns. The PDF is published in various forms, including index cards, microfiche, and books, and is divided into Inorganic and Organic & Organometallic subsets. The JCPDS uses computer-readable forms and time-sharing networks for searching and matching patterns. Computer-aided editorial evaluation is being used to enhance the reliability and quality of the data, with programs like NBS-AIDS80 for evaluating and editing entries.The chapter discusses the use of the Metal Data File (MDF) for checking data in Structure Reports and calculating powder patterns for the Powder Data File (PDF) published by the Joint Committee on Powder Diffraction Standards. The PDF is also used to send relevant data on metals to Crystal Data. The MDF includes routines for displaying Frank-Kasper domains, coordination polyhedra, and bonds, as well as search routines for specific compounds. The file is currently available for private use but is being made publicly accessible through the Canada Institute for Scientific and Technical Information (CISTI). The Protein Data Bank (PDB) is introduced as a computer-based archival file for structural data on biological macromolecules, containing atomic coordinates for over 100 distinct molecules, including RNA, DNA, polysaccharides, and proteins. The PDB is distributed upon request from various centers and includes user-friendly computer programs for extracting information. The JCPDS (International Centre for Diffraction Data) is the publisher of the Powder Diffraction File (PDF), which is used for identifying crystalline phases through x-ray powder diffraction patterns. The PDF is published in various forms, including index cards, microfiche, and books, and is divided into Inorganic and Organic & Organometallic subsets. The JCPDS uses computer-readable forms and time-sharing networks for searching and matching patterns. Computer-aided editorial evaluation is being used to enhance the reliability and quality of the data, with programs like NBS-AIDS80 for evaluating and editing entries.