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 and can therefore lead to cures for disease.


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 or the Association.  




Once each year the ACA hosts an annual meeting at various locations throughout the United States and Canada.  Each meeting incorporates our members, fellows, plenary lecturers, speakers, poster presentations and an exhibit show.