Image Above: Red Blood Cell Membrane by David S. Goodsell, RCSB PDB and the Scripps Research Institute, 2020

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.

Call for Nominations

The ACA recognizes distinguished achievement in the field of crystallography to both mature and early career crystallographers through the presentation of various annual awards and prizes.  The ACA is now inviting nominations for its 2022 awards.  Find out how to submit a nomination and view past winners.

Bau Neutron Diffraction Award
Fankuchen Memorial Award
Kenneth N. Trueblood Award
Margaret C. Etter Early Career Award

Nominations are also being accepted for the ACA Fellows program.   View current ACA fellows and find details on how to submit a nomination.

Nomination Deadline: April 1, 2021


Winter RefleXions


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.


71st ACA Annual Meeting


CEO Action for Diversity & Inclusion™

The ACA proudly joined AIP CEO, AIP member societies CEOs, and more than 1,500 other leaders in signing the CEO Action for Diversity and Inclusion pledge, recommitting the ACA to advance diversity and inclusion in the workplace. Read more here.


Physics Societies Unite 

We have joined forces with other major physics societies to show our commitment to OA for physics research. Find out more in our joint statement.


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.