# iotbx - file readers and writers¶

The iotbx module contains most tools for reading and writing the standard formats used by both macromolecular and small-molecule crystallographers, including PDB, CIF, MTZ, and various other file types. For some formats the resulting data will be encapsulated in objects defined in cctbx and/or scitbx; others have custom classes, in particular PDB/mmCIF files which have their own complex internal representation independent of the X-ray scattering properties.