COMCIFS Never Sleeps

The Committee for the Maintenance of the CIF Standard (COMCIFS) reports that action in the last few months has seen the approval of three new Crystallographic Information File (cif) dictionaries, the first additions since the original core dictionary (version 1.0) was passed in 1990 [Acta Cryst. (1991), A47, 655-685]. In December 1996 the extended core cif dictionary (version 2.0) was approved. This evolved from the experience gained using version 1.0, particularly as a vehicle for submitting and archiving papers for Acta Cryst. C. New data items were defined and some of the definitions were clarified and a few inappropriate names changed.

The powder cif dictionary was approved in June 1997. It provides data names for the quantities normally found in reports of powder diffraction experiments and will be used, in conjunction with the core, to submit Rietveld refinements to Acta Cryst. C and to archive powder patterns in the Powder Data File produced by the International Centre for Diffraction Data.

Also in June 1997 the macromolecular CIF dictionary was approved. This mammoth document, running to some 700 pages when printed out as an ASCII file, is designed to meet the needs of those working with the structures of proteins and nucleic acids. It is being adopted as the working format for the Protein Databank and the Nucleic Acid Database. This dictionary is much more structured than the other two because of the special needs of the macromolecular community. It includes a complete set of data names corresponding to the contents of the core dictionary cast in the same formalism.

B. Toby and his team prepared the powder cif dictionary and P. Fitzgerald led the team that prepared the macromolecular cif dictionary. Full details of the new dictionaries are available on the IUCr CIF home page: http://www.iucr.ac.uk/iucr-top/cif/home.html.