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Report from COMCIFS

[I. D. Brown]I. D. Brown

Now that three basic Crystallographic Information File (CIF) dictionaries have been approved, COMCIFS (the IUCr Committee for the Maintenance of the CIF Standard) has completed the first phase of its work. The new terms of reference, recently approved by the IUCr Executive Committee, can be found at the URL:

In the past five years, the business of COMCIFS has been carried out by email in the form of eighty-five circulars distributed to its members. All these circulars can now be viewed at Since Sept. 1998, COMCIFS has conducted its business using a discussion list (archived at the same address). Only members of COMCIFS may contribute to this list directly, but anyone is free to view the discussions and to send their comments to the coordinating secretary ( for inclusion as appropriate in the discussion list.

Maintaining the three CIF dictionaries has tended to distract COMCIFS from the more central matters of philosphy and policy. Therefore COMCIFS has set up Dictionary Maintenance Groups (DMG) for each dictionary. Each of the DMGs, which are responsible for recommending changes to their respective dictionaries, archives its own discussions and these may be viewed at the URLs given below. Everyone is welcome to review these discussions and to contact the appropriate DMG with suggestions or corrections. This arrangement should allow the dictionaries to respond rapidly to the needs of the community.

Core CIF Dictionary

This dictionary provides CIF names and definitions for the basic crystallographic concepts, particularly those needed for single crystal studies of simple materials. It is the dictionary that is used for most papers submitted to Acta Cryst. C. CIF_core.dic 2.0, the currently approved version, can be found at

CIF_core.dic 2.1 is in preparation. Members of the coreDMG are: I.D. Brown (Chair):, B. McMahon (Secretary):, P. Edgington, H. Flack (Consultant), Y. Grin (Consultant), S. Hall, G. Madariaga (Consultant), G. Sheldrick (Consultant), T. Spek, J. Westbrook (Consultant). The coreDMG discussion list can be viewed at:

Powder Diffraction CIF Dictionary

This dictionary has been designed to provide the necessary items for describing powder diffraction results. It is now being used for the submission of Rietveld refinements to Acta Cryst. C and has been adopted by the Int'l Center for Diffraction Data for use in future versions of the Powder Data File. CIF_pd.dic 1.0, the current version, can be found at

Members of the pdDMG are: B. Toby (Chair):, L. Cranswick, T. Degen, B. von Dreele, J. Faber, A. Fitch, J. Rodriguez-Carvajal. The pdDMG discussion list can be found at

Macromolecular CIF Dictionary

This dictionary is used for reporting macromolecular structures and has been adopted by the Protein Databank and Nucleic Acid Databank. The latest approved version, CIF_mm.dic 1.0, can be viewed at, mirrored at

Version 2.0 is in an advanced stage of preparation. Proposed amendments can be found on the mmCIF mailing list. Members of the mmDMG are: P. Fitzgerald (Chair): (paula_fitzgerald@, H. Berman, H. Bernstein, J. Westbrook, with an editorial board consisting of F. Allen, P. Bourne, K. Henrick, A. Howard, J. Sussman, D. Tronrud.

The mmDMG has a public mailing list at: , which is archived at and at

All of the dictionaries and the discussions of the various committees can be accessed from the IUCr home page:

I. D. Brown