Crystallographic Information Framework

CIF software terms and conditions of use

Use of applications and software libraries in this collection

The programs and libraries distributed by the IUCr from its CIF web site and in association with International Tables for Crystallography: Volume G. Definition and Exchange of Crystallographic Data are supplied for the purposes of education, illustration and private or academic research. Their distribution in this way is intended as a service to provide convenient access to programs and libraries that have been placed in the public domain or that have been contributed to and by the academic community.

Where the programs or libraries carry specific licenses or information concerning their use, modification or redistribution, such licenses or information are listed in the accompanying documentation. Such explicit licenses given by the copyright owners supersede the general terms under which the software is distributed in this collection. Where no such explicit licenses are given, the software must not be used for commercial or private monetary gain, and may not be modified, sold, redistributed or incorporated in other software without the express permission of the copyright owners. Use for educational, illustrative or research purposes is permitted so long as the moral rights of the authors are respected, and suitable attribution is provided.

With respect to any software or documents for which a copyright exists, all rights are reserved to the owners of such copyright.


For all software distributed in this collection under these terms and conditions, there is no warranty for the software, to the extent permitted by applicable law. Except when otherwise stated in writing the copyright holders and/or other parties provide the program "as is" without warranty of any kind, either expressed or implied, including, but not limited to, the implied warranties of merchantability and fitness for a particular purpose. The entire risk as to the quality and performance of the program is with the user. Should the program prove defective, the user assumes the cost of all necessary servicing, repair or correction.

In no event unless required by applicable law or agreed to in writing will any copyright holder be liable to the user for damages, including any direct or indirect, special, incidental or consequential damages arising out of the use or inability to use the software (including but not limited to loss of data or data being rendered inaccurate or losses sustained by the user or third parties or a failure of the program to operate with any other programs), even if such holder or other party has been advised of the possibility of such damages.

[CIF logo]

The IUCr policy for the protection and the promotion of the STAR File and CIF standards for exchanging and archiving electronic data


The Crystallographic Information File (CIF)[1] is a standard for information interchange promulgated by the International Union of Crystallography (IUCr). CIF (Hall, Allen & Brown, 1991) is the recommended method for submitting publications to Acta Crystallographica Section C and reports of crystal structure determinations to other sections of Acta Crystallographica and many other journals. The syntax of a CIF is a subset of the more general STAR File[2] format. The CIF and STAR File approaches are used increasingly in the structural sciences for data exchange and archiving, and are having a significant influence on these activities in other fields.

Statement of intent

The IUCr's interest in the STAR File is as a general data interchange standard for science, and its interest in the CIF, a conformant derivative of the STAR File, is as a concise data exchange and archival standard for crystallography and structural science.

Protection of the standards

To protect the STAR File and the CIF as standards for interchanging and archiving electronic data, the IUCr, on behalf of the scientific community,
  • holds the copyrights on the standards themselves,
  • owns the associated trademarks and service marks, and
  • holds a patent on the STAR File.
These intellectual property rights relate solely to the interchange formats, not to the data contained therein, nor to the software used in the generation, access or manipulation of the data.

Promotion of the standards

The sole requirement that the IUCr, in its protective role, imposes on software purporting to process STAR File or CIF data is that the following conditions be met prior to sale or distribution.
  • Software claiming to read files written to either the STAR File or the CIF standard must be able to extract the pertinent data from a file conformant to the STAR File syntax, or the CIF syntax, respectively.
  • Software claiming to write files in either the STAR File, or the CIF, standard must produce files that are conformant to the STAR File syntax, or the CIF syntax, respectively.
  • Software claiming to read definitions from a specific data dictionary approved by the IUCr must be able to extract any pertinent definition which is conformant to the dictionary definition language (DDL)[3] associated with that dictionary.
The IUCr, through its Committee on CIF Standards, will assist any developer to verify that software meets these conformance conditions.

Glossary of terms

[1] CIF:
is a data file conformant to the file syntax defined at
[2] STAR File:
is a data file conformant to the file syntax defined at
[3] DDL:
is a language used in a data dictionary to define data items in terms of "attributes". Dictionaries currently approved by the IUCr, and the DDL versions used to construct these dictionaries, are listed at

Last modified: 30 September 2000