Prospective authors are invited to submit abstracts for the 27th Congress and General Assembly of the International Union of Crystallography (IUCr2026), to be held at the BMO Centre in Calgary, Canada (August 11-18, 2026). Researchers from every corner of crystallography and related disciplines are encouraged to submit their work for consideration in the program of plenaries, keynotes, microsymposia, and posters. Abstracts must be submitted through the official online submission form by February 15, 2026 (11:59 PM ET). Submissions received after the deadline will not be considered for oral presentations. Visit https://iucr2026.org to submit and abstract and for information about registration, housing, and visas.