Related Links: File Formats

The RCSB PDB offers links to software tools and descriptive resources for file formats used to describe PDB data. A few of these links include:

mmCIF Resources

Background information, Data Dictionaries (including the PDB Exchange Dictionary), Proposed Data Items for Structural Genomics Depositions, mmCIF-PDB correspondences, OMG CORBA API, and software tools

Chemical Component Dictionary and Description

The PDB Chemical Component Dictionary (formerly the HET Group Dictionary) is available in PDB and mmCIF formats. A guide to these dictionaries is available at

PDB File Format Contents Guide Version 2.2

A description of the PDB file format is available.