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.


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.  



The first issue of RefleXions for 2019 is available to our members!  Log in and check out the spring features:



The ACA celebrates International Women's Day 2019!

Ronald E. Stenkamp Living History

ACA Cincinnati/Northern Kentucky Preview


The last issue of RefleXions for 2018 has been archived and is available online.  

2019 ACA Annual Meeting Room Block Closes on

THURSDAY, JUNE 27, 2019!  


As expected, demand has been high for rooms in the ACA block.  The blocks have been adjusted and some additional rooms are now available. 

There are a number of rooms available at both hotels on July 20th, 21st, 22nd, 23rd and 24th.  If you have booked a room at a different hotel please take a moment and see if there is any availability on the days of your stay in one the ACA's room blocks.  If there is availability, please consider booking in the block.  Staying in one of the ACA room blocks is not only a convenient way to help you stay connected with activities and networking opportunities during the meeting, it also helps keep your meeting costs as low as possible.  

A single room rate is $159 per room per night (plus tax) at either the Cincinnati Marriott at RiverCenter or the Embassy Suites Cincinnati RiverCenter.

Rooms for students or postdocs are $129 per room, per night (plus tax) at either the Cincinnati Marriott at RiverCenter or the Embassy Suites Cincinnati RiverCenter.  These discounted rooms are ONLY for students and postdocs. If you make a reservation at this rate but are found to be ineligible, you will be asked to cancel and rebook at the appropriate rate. New reservations will be subject to hotel's availability.  


2019 ACA Annual Meeting: Cincinnati/Northern Kentucky

In 2018, over six hundred international individuals attended the ACA Annual Meeting in Toronto, Canada. This year attendees from around the globe will come together to discuss the latest cutting-edge developments in crystallography in Cincinnati/Northern Kentucky at the 69th ACA Annual Meeting.

We invite you to join our community and see first-hand the resources, opportunities and connections the ACA provides at every level of your scientific journey. In addition to the plethora of benefits (including publication subscriptions, opportunities to publish and networking opportunities), the largest benefit to membership is that ACA members enjoy reduced registration rates to the annual meeting.

The ACA Annual Meeting offers an amazing chance to network with scientists of all disciplines and at all levels.ACA members bring an awesome array of crystallographic specialties in any number of categories to our annual meeting, including but not limited to the subjects of CRYO-EM, Biomacromolecules, Fiber, Materials and Powder.

Take advantage of this opportunity and utilize your membership to the fullest.