notes for authors

1. Scientific scope

IUCrData is a peer-reviewed open-access journal from the International Union of Crystallography (IUCr). This innovative publication aims to provide short descriptions of crystallographic datasets and datasets from related scientific disciplines, as well as facilitating access to the data. There are two primary article categories: Raw Data Letters and Data Reports. Raw Data Letters publish short descriptions of crystallographic raw data sets in the biological, chemical or materials science fields, allowing researchers to attract attention to particular features of the data that could be of interest to methods and software developers or may be relevant to the structural interpretation. Information for each dataset includes an imgCIF containing core metadata, a diffraction image, figures, and a description of the data and their processing. The journal adheres to the FAIR principles, for which the correctness and completeness of the metadata are crucial. Data Reports describe crystal structures of inorganic, metal-organic or organic compounds. Information on each crystal structure includes the crystallographic data (CIF and structure factors), a data validation report, figures and a text representation of the data.

2. Submission requirements

Guidelines for the preparation and editing of articles are available from the author services page at The Main Editors, Co-editors and Editorial Office staff are available to assist authors with any technical matters.

A single author (the submitting author) should handle the submission of the article and be the contact for any editorial questions during the review and publication processes. The submitting author should provide an institutional e-mail address. The published article may have one or more authors (correspondence authors) who are responsible for communications after publication and are marked with an asterisk in the published article. All authors are strongly encouraged to provide an ORCiD iD during submission.

Authors will be asked to agree to an open-access licence (see Section 2.7[link]), and will also be asked to confirm that they can pay the open-access fee, or that they have a payment waiver (see Section 5.5[link]).

During submission authors will be encouraged to provide a tweet about their article for use on publication; twitter handles for departments, institutions etc. will also be requested.

2.1. Submission of Raw Data Letters

Raw Data Letters should be submitted at Authors are encouraged to use the template available from

The source files required for a letter are: a single file in Word or OpenDocument format of the text, tables and figures of the letter; a high-resolution graphics file (minimum 600 d.p.i.) in TIFF, PostScript, encapsulated PostScript or PNG format for each figure and scheme (see Section 3.2[link]); an imgCIF file containing the metadata for the raw data files, a persistent indentifier (doi) for the location of the raw data, and files of any supporting information. Tools will be available for setting up an imgCIF geometry file for your beamline or equipment, or for converting metadata header information from your image data to full imgCIF. Supporting information should be provided in one of the formats listed at Files should be uploaded as described in the online submission instructions.

2.2. Submission of Data Reports

All Data Reports should be submitted in Crystallographic Information File (CIF) format. A free CIF editor for authors, publCIF, may be obtained from

Authors are required to validate their CIF and structure factors using the checkCIF service at before submission. Validation alerts returned by checkCIF should be resolved where possible before proceeding. In some cases, a validation response form (VRF) will be supplied by checkCIF. If the related validation issue cannot be resolved, this form should be completed as described in the author services page at, preferably with the addition of appropriate explanatory text in the experimental section of the CIF. A preview of the CIF may be generated using the printCIF service at or by using publCIF.

2.3. Handling of articles

Articles considered suitable for peer review will be assigned to a Co-editor. The Co-editor is responsible for the review steps and future communications with the authors up to the acceptance stage. This responsibility includes decisions on the final form of the article and interpretation of these Notes for Authors when necessary. Further information on the peer-review process can be found at

Changes to a manuscript requested by a Main Editor, Co-editor or the editorial staff should be received within one month of transmittal to the author, otherwise the submission will be considered as withdrawn. If a manuscript is not acceptable after two revisions it will not be considered further. Any subsequent communication of the material will be treated as a new submission in the editorial process.

After initial submission, any revised or new files should be uploaded only in response to a specific request from an editor.

On acceptance, the author will also be asked to pay the open-access fee or provide a waiver. For accepted articles, it is the responsibility of the Managing Editor to prepare the article for publication. This may involve correspondence with the authors and/or the Co-editor in order to resolve ambiguities or to obtain satisfactory figures or tables. The date of acceptance that will appear on the published article is the date on which the Managing Editor receives the last item required. Correspondence will be sent to the submitting author unless the Managing Editor is informed of some other suitable arrangement. Contact details for the Managing Editor of IUCrData can be found at

Articles may be checked for plagiarism using the Crossref Similarity Check service.

Co-editors may request any additional experimental data or material they feel necessary to complete a full review of the article.

2.4. Transfer of articles

On rare occasions, editors may suggest the transfer of an article to another IUCr Journal, if the article appears to be more suited to the other journal. The transfer process is rapid, as articles can be seamlessly transferred from one journal to another together with the corresponding reviews. The editor of the new journal will often make a decision based on the existing reviews, but will sometimes invite additional reviewers. Note that any change to the journal of publication will only be made after full discussion with the submitting author.

2.5. Author's warranty and ethical considerations

The submission of an article is taken as an implicit guarantee that the work is original, that it is the author(s) own work, that all authors are aware of and concur with the submission, that all workers involved in the study are listed as authors or given proper credit in the Acknowledgements, that the manuscript has not already been published (in any language or medium), and that it is not being considered and will not be offered elsewhere while under consideration for IUCrData. The prior inclusion of material in an informal publication, e.g. a preprint server, is welcomed by IUCr Journals.

The co-authors of an article should be all those persons who have made significant scientific contributions to the work reported, including the ideas and their execution, and who share responsibility and accountability for the results. Other contributions should be indicated in the Acknowledgements. Authors are encouraged to provide a paragraph in the Acknowledgements giving the specific contributions made by each author (for more details see the online submission instructions). Changes to the list of authors will normally require the agreement of the editor and all authors.

The IUCr is a member of COPE (Committee on Publication Ethics) and endorses its recommendations, including the Code of Conduct for Editors, which are available at Important ethical considerations related to publication have been given in the guidelines published in Acc. Chem. Res. (2002), 35, 74–76 and Graf et al. [Int. J. Clin. Pract. (2007), 61(Suppl. 152), 1–26]. Authors are expected to comply with these guidelines. Further details of the ethical policies of IUCr Journals can be found at

Authors publishing in the journal may be asked to review articles submitted to the journal.

2.6. Author grievance procedure

An author who believes that an article has been unjustifiably treated by the Co-editor may appeal initially to the Main Editors for a new review and, finally, to the Editor-in-chief of IUCr Journals if still aggrieved by the decision. The initial appeal should be made within three months of rejection of the article. The decision of the Editor-in-chief is final.

2.7. Licencing

Authors will not be asked to transfer copyright to the IUCr, but will instead be asked to agree during article submission to an open-access licence. This licence is identical to the Creative Commons Attribution (CC-BY) Licence. Details of author rights can be found at

3. Publication and data requirements

3.1. Article text

Articles should be clearly and simply written so that they are accessible to as broad a readership as possible. Before preparing articles, authors should consult a current issue of the journal to make themselves familiar with the general format, such as the use of headings, layout of tables and citation of references.

The title of the article should be written to appeal to a wide audience and should include key phrases in the subject area. The most effective titles are generally no more than 10–12 words in length. The use of acronyms or abbreviations should be avoided.

All contributions should be accompanied by an English language Abstract and a one- or two-sentence Synopsis of the main findings of the article for inclusion in the contents pages. The Abstract should state as specifically and as quantitatively as possible the principal results obtained, and should provide an indication of the broader significance of the work. Authors should also supply at least five keywords. These may include synonyms and specific phrases related to the subject of the article.

The Abstract should be suitable for reproduction by abstracting services without change in wording. It should make no reference to tables, diagrams, atom numbers or formulae contained in the article. It should not contain footnotes and should not include the use of `we' or `I'.

The description of the preparation of samples should give sufficient information on the isolation or synthesis of the compound, crystal preparation (method, solvents and their ratios), and identification (e.g. melting points, optical rotation), to reproduce the experiment. Previously reported syntheses, isolation procedures or spectroscopic data need only be cited.

3.2. Diagrams and photographs (`figures')

A set of guidelines for preparing figures is available from A high-resolution graphics file (minimum 600 d.p.i.) in TIFF, PostScript, encapsulated PostScript, JPEG or PNG format is required for each figure and scheme.

The choice of figures should be optimized to produce the shortest article consistent with clarity. Duplicate presentation of the same information in both tables and figures is to be avoided, as is redundancy with the text. Supplementary figures may be deposited (see Section 4[link]).

An image which summarizes the message of the paper, and can be used as a thumbnail on the contents pages and the first page of the article, should be provided.

3.2.1. Quality

Electronic files in the formats listed in Section 3.2[link] are essential for high-quality reproduction.

3.2.2. Size

Diagrams should be as small as possible consistent with legibility. They will normally be sized so that the greatest width including lettering is less than the width of a column in the journal (8.8 cm).

3.2.3. Lettering and symbols

Fine-scale details and lettering should be large enough to be clearly legible (ideally 1.5–3 mm in height) after the whole diagram has been reduced to one column width.

Lettering should be kept to a minimum; grids and shadings should be avoided where they are not required for clarity. Descriptive matter should be placed in the caption.

3.2.4. Numbering

Diagrams should be numbered in a single series in the order in which they are referred to in the text.

3.3. Tables

3.3.1. Use of tables

Extensive numerical information is generally most economically presented in tables. Text and diagrams should not be redundant with the tables.

3.3.2. Design, numbering and size

Tables should be numbered in a single series of arabic numerals in the order in which they are referred to in the text. They should be provided with a caption.

Tables should be carefully designed to occupy a minimum of space consistent with clarity.

3.4. Mathematics and letter symbols

The use of the stop (period) to denote multiplication should be avoided except in scalar products. Generally, no sign is required but, when one is, a multiplication sign (×) should be used.

Scalar variables and non-standard functions should appear in italic type.

Vectors should be in bold type and tensors should be in bold-italic type.

Greek letters should not be spelled out.

Care should be taken not to cause confusion by using the same letter symbol in two different meanings.

Gothic, script or other unusual lettering should be avoided. Another typeface may be substituted if that used by the author is not readily available.

All displayed equations should be numbered in a single series.

3.5. Funding information

Articles may include a Funding information section. This section aims to help authors comply with the reporting requirements of funders, and includes information on funders and grant/award numbers. Funding information should not be included in the Acknowledgements section. For more information, see

3.6. Nomenclature

3.6.1. Units

The International System of Units (SI) is used except that the ångström (symbol Å, defined as 10−10 m) is generally preferred to the nanometre (nm) or picometre (pm) as the appropriate unit of length. Recommended prefixes of decimal multiples should be used rather than `× 10n'.

3.6.2. Nomenclature of chemical compounds etc

Names of chemical compounds and minerals are not always unambiguous. Authors should therefore quote the chemical formulae, including chemical structural diagrams for organic and metal-organic compounds, of the substances dealt with in their articles.

Chemical formulae and nomenclature should conform to the rules of nomenclature established by the International Union of Pure and Applied Chemistry (IUPAC), the International Union of Biochemistry and Molecular Biology (IUBMB), the International Mineralogical Association (IMA) and other appropriate bodies. As far as possible, the crystallographic nomenclature should correspond to the systematic name.

For crystal structures containing chiral molecules, authors should make it clear whether the crystal structure is a racemate or enantiopure, and if enantiopure whether or not the assignment of the absolute configuration is justified. The title, com­pound name, chemical diagrams, atomic coordinates and space group should correspond with the enantiomeric composition and the selected configuration.

3.6.3. Crystallographic nomenclature

Authors should follow the general recommendations produced by the IUCr Commission on Crystallographic Nomenclature (see reports at

Space groups should be designated by the Hermann–Mauguin symbols. Standard cell settings, as listed in Volume A of International Tables for Crystallography, should be used unless objective reasons to the contrary are stated. When a non-standard setting is used, the list of equivalent positions should be given. Hermann–Mauguin symbols should also be used for designating point groups and molecular symmetry. It is helpful if the origin used is stated explicitly where there is a choice.

The choice of axes should normally follow the recommendations of the Commission on Crystallographic Data [Kennard et al. (1967). Acta Cryst. 22, 445–449].

A symbol such as 123 or hkl without brackets is understood to be a reflection, (123) or (hkl) a plane or set of planes, [123] or [uvw] a direction, {hkl} a form and 〈uvw〉 all crystallographically equivalent directions of the type [uvw]. Other bracket notations should be explicitly defined.

3.6.4. Biochemical nomenclature

The recommendations of the Nomenclature Committee of IUBMB and the IUPAC-IUBMB Joint Commission on Biochemical Nomenclature (see should be followed as far as practicable. The recommendations of the latest edition of Enzyme Nomenclature (1992, San Diego: Academic Press; and its supplements) should be followed as far as possible (see This includes the quoting of EC numbers. It is recommended that authors use the nomenclature for restriction enzymes, DNA, methyltransferases, homing endonucleases (and their genes) proposed by Roberts et al. [(2003), Nucleic Acids Res. 31, 1805–1812].

3.7. References

References to published work should be indicated by giving the authors' names followed immediately by the year of publication, e.g. Neder & Schulz (1998) or (Neder & Schulz, 1998). Where there are three or more authors, the reference in the text should be indicated in the form Smith et al. (1998) or (Smith et al., 1998).

In the reference list, entries should be arranged alphabetically and conform with the following style:

Bond, A. D. (2012). Acta Cryst. E68, o1992–o1993.

Brink, A. & Helliwell, J. R. (2019). Raw diffraction images. Formation of a highly dense tetra rhenium cluster in a protein crystal and its implications in medical imaging.

Cowley, J. M. (1993). Editor. Electron Diffraction Techniques. Oxford University Press.

CRC Handbook of Chemistry and Physics (1983). 64th ed., edited by R. C. Weast, p. D-46. Boca Raton: CRC Press.

Cruickshank, D. W. J. (1998). Acta Cryst. A54, 687–696.

Ferguson, G., Schwan, A. L., Kalin, M. L. & Snelgrove, J. L. (1997). Acta Cryst. C53, IUC9700009.

Götz, D., Herres, N., Diehl, R. & Klapper, H. (2022). In preparation.

International Union of Crystallography (2022). (IUCr) International Union of Crystallography,

Khoshouei, M., Radjainia, M., Baumeister, W. & Danev, R. (2016). bioRxiv,

Lutz, M. & Kroon-Batenburg, L. (2022). IUCrData, 7, Submitted.

Neviani, V., Lutz, M., Oosterheert, W. Gros, P. & Kroon-Batenburg, L. (2022). IUCrData, 7, Submitted.

Petit, G. A., Mohanty, B., McMahon, R. M., Nebl, S., Hilko, D. H., Wilde, K. L., Scanlon, M. J., Martin, J. L. & Halili, M. A. (2021). bioRxiv,

Reyes, A. A., Fishbain, S. & He, Y. (2022). Acta Cryst. F78,

Schowalter, M., Müller, K. & Rosenauer, A. (2012). Acta Cryst. A68,

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Shmueli, U. & Weiss, G. H. (1985). Structure and Statistics in Crystallography, edited by A. J. C. Wilson, pp. 53–66. Guilderland: Academic Press.

Smith, J. M. (2022). Acta Cryst. D78. In the press.

Wall, M. E. (2015). arXiv:1511.07811.

Zhou, P. F. (1993). PhD thesis, McMaster University, Hamilton, Ontario, Canada.

Note that all authors and inclusive page numbers should be given.

Identification of individual structures in an article by use of database reference (identification) codes should be accompanied by a full citation of the original literature in the reference list. Citations in the supporting information should also appear in the main body of the article or be given in a related literature section. Where authors have used a publicly available data set from a repository this should be cited in the published article.

3.8. Data policy

In order that others can reproduce, verify and build on the work published in IUCr Journals, authors are expected to make supporting data freely available. In this context, the IUCr has adopted a data-sharing policy that requires the data supporting the results in a structural article to be peer reviewed and archived either with the IUCr or in an appropriate public repository. For peer-review purposes, authors are asked to provide access to their data on submission.

Although the Raw Data Letters section of IUCrData does not normally publish structure determinations, in the case of a structure being published, authors should follow the guidelines for data requirements for the type of structure that is being reported. Authors who report the results of crystal structure determinations of small molecules or materials must supply data as a single electronic file in CIF format. Structure factor data in CIF format are also required. For letters that report the results of structure determinations of biological macromolecules, authors should consult the Acta Cryst. D Notes for Authors for details of data requirements.

Authors of powder diffraction articles should consult the notes provided at For articles that present the results of powder diffraction profile fitting or refinement (Rietveld) methods, the primary diffraction data, i.e. the numerical intensity of each measured point on the profile as a function of scattering angle, must be deposited.

Some specific data requirements for Raw Data Letters and Data Reports are outlined below and on the author services page at This page also provides links to data requirements for different types of structures and different structure determination techniques.

3.9. Requirements for Raw Data Letters

In addition to an Abstract, Raw Data Letters should normally include Data processing and refinement and Data description sections. Authors are required to supply core metadata for the raw data and a diffraction image. The raw data should be archived in a recognized repository that assigns a persistent identifier (doi) to the data. For more information, see the online submission instructions.

In the Data processing section, details of how the data were processed should be supplied, as well as any particular strategies employed in the model refinement, if a 3D molecular structure was reached, for example to deal with disorder or twinning in the processed diffraction data step or later in the model refinement step. Overlap between this section and the Data description section should be kept to a minimum. If the structure has been published, a reference to the article reporting the structure should be given.

A description of any notable features in the diffraction images should be given in the Data description section. The description should include details of streaks, twinning, disorder etc., together with a brief outline of how and where the data were obtained.

Core metadata should be provided in imgCIF format and also included in an Experimental table in the article. These metadata include a doi for the raw data, the name of the dataset and a description of the data, the beamline or difractometer used, detector type, data binary format and compression type, binning mode, beam centre, wavelength, wavelength bandpass, orientations of all goniometer and detector axes (using imgCIF conventions), specification of rotation axis, start angle and increment per frame (direction: positive or negative), pixel size, detector distance, and number of frames. A list of core metadata is available from Kroon-Batenburg et al. (2022). IUCrData, 7, x220821.

A raw diffraction image should be provided for each Raw Data Letter. Authors will also be asked to supply an additional image for the first page of the letter; this might be a view of the 3D structure if solved, a photograph of crystals, a chemical scheme, a powder diffraction pattern etc. Additional diagrams may be included to illustrate the features discussed in the text.

3.10. Requirements for Data Reports

In addition to an Abstract, Data Reports should normally include Structure description and Synthesis and preparation sections. The Refinement section will only be published if it reports non-routine procedures. A chemical scheme is published for metal-organic and organic compounds. Authors are required to supply an ellipsoid plot for molecular species and a polyhedral plot for inorganic compounds.

The Structure description section contains any comments about the structure. Overlap between this section and the Abstract should be kept to a minimum. Together they should include: a brief description of the molecule with salient features; a brief summary of the packing features; a related structure or structures for comparison; the relevance of the molecule or background to the study.

The latest version of the refinement software should be used. Authors should include copies of their refinement instructions file(s) and input reflection data file(s), where available, in the submitted CIF (for more details, see the author services page at

All symmetry-unique bond lengths and angles, as well as those involving H atoms, should be included in the CIF; the additional inclusion of torsion angles for non-H atoms is encouraged. This is usually a selectable instruction in the refinement program. All geometry data will be placed in the supporting information available to readers.

For Data Reports, tables of bond lengths, angles and torsion angles will be generated automatically from parameters flagged for publication in the CIF. Values that are of special interest and are discussed in the text should be included in these tables. Tables of hydrogen bonds can similarly be created and can usually be generated by the refinement program. Other desired tables, such as a comparison of parameters, can be included using the extra table facility in publCIF or as described at

A chemical structure diagram should be included in a Data Report for all but inorganic compounds with extended framework structures. The diagram should show all species present in the structure, including counter-ions and solvent molecules in their correct proportions. For polymeric structures, the connectivity to the next repeat units should be indicated. Any relative or absolute stereochemistry should be shown.

Authors are also encouraged to submit chemical connectivity (MOL, CML, CHM, SMI) files of reported structures; these can often be generated by the software used to generate the scheme.

4. Additional supporting information

Additional supporting information (such as experimental analyses, additional figures and multimedia content) that may be of use or interest to some readers but does not form part of the article itself will be made available from the journal website. Arrangements have also been made for such information to be deposited, where appropriate, with relevant databases.

Multimedia content (e.g. time-lapse sequences, three-dimensional structures) is welcomed. The preferred file formats for multi­media are given at

5. Author information and services

An author services page is available at

5.1. Author tools

A number of tools are available to help with the preparation of articles.

(a) Templates for preparing articles can be downloaded from the author services page.

(b) The checkCIF/PLATON service at allows CIFs and structure factors to be checked.

(c) For Data Reports, CIFs can be edited using publCIF, available from, and previewed using the printCIF service at

(d) For Raw Data Letters, tools will be available for setting up an imgCIF geometry file for your beamline or equipment, or for converting metadata header information from your image data to full imgCIF.

5.2. Status information

Authors may obtain information about the current status of their articles at

5.3. Proofs

Proofs will be provided electronically in portable document format (pdf). The submitting author will be notified by e-mail when the proofs are ready for downloading.

5.4. Reprints

After publication, the submitting author will be able to download an electronic reprint of the published article, free of charge.

5.5. Open access

IUCrData is an open-access publication. The costs of peer review, of production, and of online hosting and archiving will be met by charging an open-access fee to authors.

Authors will be asked to pay an open-access fee upon acceptance of their article for publication. Authors from developing countries may apply for their open-access fees to be waived. Waiver requests should be made before submission of an article to the journal.

Full details of the open-access arrangements for IUCrData are available at

5.6. Publication and social media

IUCrData is available on the web at Once your article has been published it will also appear on Twitter @IUCrData.

5.7. Publicizing your article

There are many ways in which the IUCr promotes and raises awareness of articles published in its journals. More information on this and suggestions on how to publicize your articles can be found at

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