2. CIF - The Crystallographic Information File

The small-molecule Crystallographic Information File (CIF: Hall, Allen & Brown, Acta Crystallographica, A47, 655-685, 1991) is a universal format for the electronic storage and exchange of crystallographic information. It has been adopted as the international standard for this purpose by the International Union of Crystallography (IUCr), and is used in:

·        Assembling laboratory archives.

·        Transferring crystallographic information between laboratories.

·        Depositing crystallographic information with most major journals.

·        Depositing data with the crystallographic databases.

·        As a database output format, e.g. for entries retrieved from the Cambridge Structural Database.

A CIF is an electronic ASCII file, which is intended to be human readable and editable. It consists of a set of data items which may appear individually or in looped lists. The lines in a CIF must not exceed 2048 characters in length, although a soft limit of around 80 characters per line is often used for easy readability and to ensure facile transmission via e-mail.

Full details of the small-molecule CIF, including leading references, can be found on the IUCr website at http://www.iucr.org/, and only a brief general introduction is provided here.