The Protein Data Bank (PDB) format provides a standard representation for macromolecular structure data derived from X-ray diffraction and NMR studies. This representation was created in the 1970's and a large amount of software using it has been written.
Documentation describing the PDB file format is available from the wwPDB at http://www.wwpdb.org/docs.html.
Historical copies of the PDB file format from 1992* and 1996* are available.
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