checkCIF: online structure validation service

checkCIF is a service operated by the International Union of Crystallography (IUCr) for checking structural data destined for publication in journals or database deposition; it may also be used by scientists wishing to assess the quality of their structure determinations whether they intend to publish them or not.

The service (http://checkcif.iucr.org) allows anonymous upload, over the web, of structural data sets in CIF format (http://www.iucr.org/resources/cif). The resulting report appears within a short time in the browser window.

The tests carried out by checkCIF include:

1. a simple file syntax check;
2. tests for the self-consistency of mutually dependent data items present in the CIF;
3. a large collection of analytic tests on structural chemistry and molecular geometry based on the program PLATON (Spek, 2009).

The checks carried out are listed in detail on the IUCr journals web site (http://journals.iucr.org/services/cif/datavalidation.html).

The results from checkCIF provide valuable indications of possible inconsistencies or data errors, and are used by some journals in their peer review procedures. Articles are not, however, accepted or rejected on the basis of the checkCIF report alone. The report is always read by a reviewer as part of a considered critical appraisal of the article.

_{Spek, A. L. (2009). Structure validation in chemical crystallography. Acta Cryst. D65, 148-155. http://dx.doi.org/10.1107/S090744490804362X}