Welcome to the
International Union of Crystallography

The IUCr is an International Scientific Union. Its objectives are to promote international cooperation in crystallography and to contribute to all aspects of crystallography, to promote international publication of crystallographic research, to facilitate standardization of methods, units, nomenclatures and symbols, and to form a focus for the relations of crystallography to other sciences. Read more »


  • Crystallographers unite to tackle coronavirus

    With stories about coronavirus dominating the news, we report that crystallographers around the world are making strong contributions to the efforts to find a vaccine and advance therapeutics.

  • Trust Science Pledge

    The message of the International Day of Light 2021 – Trust Science – encourages both scientists and the public alike to sign and support a declaration affirming their trust in science and the importance of public confidence in the scientific process.

  • 25th IUCr Congress and General Assembly

    The IUCr Executive Committee has decided that the Congress will definitely go ahead in August 2021. At present, it is hoped that the Congress and General Assembly will both be a hybrid of online and in-person participation.

  • Sidney C. Abrahams

    We are sad to report the death of Sidney C. Abrahams at the age of 96. Dr Abrahams was Editor of Acta Crystallographica from 1978 to 1987.

  • Bond Valence Parameters data set

    An update to the Accumulated Table of Bond Valence Parameters maintained by I. D. Brown is available from the IUCr website.

The best in crystallographic research

Uniquely among International Scientific Unions, the IUCr publishes its own primary research journals. Acta Crystallographica Sections A–F, IUCrJ, Journal of Applied CrystallographyJournal of Synchrotron Radiation and IUCrData communicate the highest quality peer-reviewed research findings across the many scientific areas to which crystallography is relevant.

[Prague 2020 logo]

25th IUCr Congress

Prague, Czech Republic
14-22 August 2021

Regional Associate meetings
[ACA logo]
30 July-5 August 2021

[AsCA logo]
6-9 December 2021

[ECA logo]
ECM33 Versailles, France
23-27 August 2022

to be announced

IUCr Corporate Associates

Category 1
Category 1
Category 1
Category 2
Category 3
International Union of Crystallography

Scientific Union Member of the International Science Council (admitted 1947). Member of CODATA, the ISC Committee on Data. Partner with UNESCO, the United Nations Educational, Scientific and Cultural Organization in the International Year of Crystallography 2014.

International Science Council Scientific Freedom Policy

The IUCr observes the basic policy of non-discrimination and affirms the right and freedom of scientists to associate in international scientific activity without regard to such factors as ethnic origin, religion, citizenship, language, political stance, gender, sex or age, in accordance with the Statutes of the International Council for Science.