Structure Matters!

Welcome to the American Crystallographic Association. The American Crystallographic Association, Inc. (ACA) is a non-profit, scientific organization of over a thousand members in more than thirty-five countries. The ACA was founded in 1949 through a merger of the American Society for X-Ray and Electron Diffraction (ASXRED) and the Crystallographic Society of America (CSA). The objective of the ACA is to promote interactions among scientists who study the structure of matter at atomic (or near atomic) resolution. These interactions will advance experimental and computational aspects of crystallography and diffraction. Understanding the nature of the forces that both control and result from the molecular and atomic arrangements in matter will help shed light on chemical interactions in nature.

RefleXions | Summer 2020



Membership in the ACA is open to any person who is actively interested in the purposes of the Association. The ACA welcomes everyone from students to retirees. All of our members contribute to the life and vigor of the Association.

Your membership helps the ACA share our scientific passions and accomplishments through different approaches, including the annual conference, our publications and educational outreach.

The ACA was established to connect scientists and anyone interested in crystallography and the ACA strives to continue to reach that goal today. As we progress forward the ACA remembers and memorializes our past crystallographic discoveries and achievements. It is with our history and achievements that the ACA hopes to inspire future generations of explorers, scientists and crystallographers.

As a student, let the ACA inspire you to dive into physics, math and chemistry. As a grad or undergrad let the ACA help you establish your professional network. Regular members share research, accomplishments and curate industry connections. Retired members help remember our history and encourage future crystallographers.


ACA 2020 Annual Meeting


This year’s annual meeting will be held on-line and will include a special COVID-19 session, plenary lectures from 2020 ACA Award winners, invited and contributed talks, poster presentations, and practical workshops.  The conference will meet 11 am to 4 pm EDT, Sunday, August 2 through Friday, August 7.  This conference will feature the latest research results and instructional presentations, across topics of interest to all scientists who need to understand the arrangement of atoms in matter. Scientists interested in molecular and materials structure, with specialties in biology, chemistry, geosciences, materials science and more, will want to participate to exchange scientific research findings and technique know-how.  


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Public Meeting Page
Press Release
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Molecular Storytelling Helps Diverse Audiences Understand Biomolecular Science
Visual, interactive storytelling teaches public, educators, students about biomolecular science.
Press Release
X-Ray Scattering Facility for Extreme Biology Opens for Research
Biological tools at Cornell’s synchrotron are available for understanding molecular behavior at high pressures.


Special Article: Crystallography & COVID-19

With new cases of the coronavirus disease 2019 (COVID-19) climbing steeply across the globe, everyone has an interest in solving COVID-19 challenges, but crystallography has a special role to play.  Read an overview about structural science and COVID in a special article published through the ACA.