Acronym and file extension in crystallography: cif for crystallographic information file or framework

CIF stands for crystallographic information file. It was designed as “a general, flexible and easily extensible free-format archive file; it is human and machine readable and can be edited by a simple text editor” [1]. Plain-text files in CIF format provide a standard for the exchange of crystallographic data. A CIF file contains information such as the chemical name and the composition of a crystalline compound or material, unit cell parameters and lattice coordinates, space group assignment and a reference to the original publication of the data.

The acronym CIF also stands for crystallographic information framework, sponsered and defined by the International Union of Crystallography (IUCr) as “ a broader system of exchange protocols based on data dictionaries and relational rules expressible in different machine-readable manifestations, including, but not restricted to, Crystallographic Information File and XML” [2].

The CIF format is used by fee-charging enterprise as well as open-access services; for example, the Inorganic Crystal Structure Database (ICSD) and Crystallography Open Database (COD) [3], respectively .

Keywords: crystallography, data exchange standard file format, electronic data transmission, ASCII file

References
[1] S. R. Hall, F. H. Allen and I. D. Brown: The Crystallographic Information File (CIF): a New Standard Archive File for Crystallography. Acta Cryst. A 1991, 47, pp. 655-685 [www.iucr.org/__data/iucr/cif/standard/cifstd1.html].
[2] International Union of Crystallography (IUCr): CIF [www.iucr.org/resources/cif].
[3] S. Gražulis et al.: Crystallography Open Database - an open-access collection of crystal structures. J. Appl. Cryst. 2009, 42, pp. 726-729.
DOI: 10.1107/S0021889809016690.