Having data available in a structured, subject specific database carries significant benefits. Such databases typically: allow deposition in native formats, maximising potential for analysis, reuse, and verification; deliver tools such as search, filter, and statistics functions; and provide rules to ensure that data are tidy and have a common structure and collection of metadata.
In small molecule single crystal X-ray diffraction, the Cambridge Crystallographic Data Centre (CCDC) has provided such a service for over 50 years, and the Cambridge Structural Database that they curate now holds over 900,000 entries. Although the curated database isn’t Open Access, they ensure that every individual structure, including structure factors, is accessible and free of charge to everyone (https://www.ccdc.cam.ac.uk/structures).
To support data sharing, and encourage greater transparency, we’ve updated our guidelines on the deposition of new small molecule single crystal X-ray diffraction data. They are as follows:
We recommend the use of SHELXL (2014 or later) for data processing, which embeds both the results file and structure factors into the finalized crystallographic information file (CIF) (see http://journals.iucr.org/c/services/shelxl.html for more information).
We strongly encourage that all new small molecule single crystal X-ray diffraction data be deposited with the CCDC (https://www.ccdc.cam.ac.uk/deposit) prior to submission of your article. The CCDC number(s) assigned to your structure(s) should be listed in the data availability statement, which permits retrieval of the crystallographic data for peer review purposes, and allows readers to find them once the article is published.
We would also ask you to check the integrity of your data using the IUCr’s checkCIF service (available here: http://checkcif.iucr.org/) and address significant unresolved problems (typically all A- and B-alerts) in the Validation Response Form portion of the CIF. The generation of the checkCIF report and the response to A- and B-alerts can also all be done through the deposition to the CCDC.
If you choose to not deposit your data in the CCDC prior to submission, you must upload your CIF (and RES and HKL/FCF files if necessary), along with a pdf of the checkCIF report (link above) as Supporting Information, at the same as uploading your manuscript. At acceptance, you should then submit your crystal data to an appropriate repository, and update the Data Availability statement in your manuscript to indicate how authors can retrieve the data.
A labeled ORTEP plot of [GaCl3(btd)2] showing 30% probability ellipsoids. Reproduced from https://www.hindawi.com/journals/bca/2010/168030/
The illustration and text in this blog post are by Hindawi and are distributed under the Creative Commons Attribution License (CC-BY). The ORTEP plot is by the authors of the referenced paper, which was published CC-BY.