Welcome to the History Portal of the American Crystallographic Association 

LINK: Meet Structural Scientists LINK: ACA Beginnings LINK: Videos/Audios

LINK: Nobel Prize Winners LINK: Impact of Structural Science LINK: Crystallography in the Americas

Click on Meet Structural Scientists to see the People List. Over 100 crystallographers and structural scientists are featured. 


Latest Additions 


Margaret C. Etter, whom the ACA Etter Award honors, gave three important lectures which have been placed on YouTube by the University of Minnesota. They are thoughtful and clear presentations on the following topics:

It is especially valuable to have the person who originated the “Etter Rules” – applying graph sets to hydrogen bonding patterns in the solid state – talk about graph sets!



At the White House in October Gregory Petsko received the National Medal of Science, “for advancing our understanding of neurodegenerative diseases like ALS, Alzheimer’s, and Parkinson’s.” the press release said. “His role in founding structural enzymology, along with his commitment to educating the public about brain health, have empowered people around the world and raised the ambitions of our nation regarding aging with dignity.” See, for instance, Petsko’s 2016 TED talk, “The Coming Epidemic of Neurodegenerative Diseases.” Much of his work on structural enzymology was done in collaboration with Brandeis Professor of Biochemistry and Chemistry Emerita Dagmar Ringe.


Helen M. Berman has been elected to the National Academy of Sciences.

The video of Kristin M. Hutchins’ 2023 Etter Award lecture is now online. In her presentation, "The Dynamic Side of Crystals: How Structure Influences Function in the Solid State"  she describes how hydrogen and halogen bonding, as well as other intermolecular interactions are important in the thermal stability of solids. She also discusses the use of mixed cocrystals (i.e., cocrystal solid solutions) as a strategy for fine-tuning dynamic behaviors in organic solids.


Brian Toby’s commentary, “Crystallographic hallucinations,” presents several interesting conclusions from recent work on the structure of psilocybin (Sherwood, A. M., Kargbo, R. B., Kaylo, K. W., Cozzi, N. V., Meisenheimer, P. & Kaduk, J. A. (2022). Acta Cryst. C78, 36–55.). The results from single-crystal and powder diffraction agreed and were further validated by plane-wave density functional theory (DFT). Toby concludes, “powder diffraction crystallography can rise to the gold standard level that we expect from single-crystal analysis.” Another take-away from the research is the value of DFT for crystallographers. An interesting sidelight is the brief biography of Walter Kohn, who was rescued by the British during WWII and later immigrated to the US, where he won the Nobel Prize for DFT.


Maureen Julian presents an engaging view of Dame Kathleen Lonsdale’s crystallography group at University College London, complete with historical photographs. She followed up on the careers of the group members; it is interesting to see the variety of paths that each member of the lab followed. See "The laboratory of Dame Kathleen Lonsdale at University College London from 1966 to 1968 and then fifty years later.


The prestigious Ewald Prize was awarded to Wayne Hendrickson in 2023 at the 26th IUCr Congress in Melbourne, Australia. The text of his lecture “Facing the Phase Problem” is now online. Also, see Janet Smith’s summary of his scientific career and achievements, "Commentary on `Facing the phase problem' by Wayne Hendrickson”.


Time-resolved X-ray spectroscopy on a picosecond or femtosecond scale makes it possible to study molecular rotation, isomerization, and vibration. Maged Chergui has been a pioneer in using pump-probe methods at synchrotrons to excite the molecule of interest and then follow its relaxation on ultrafast time scales, in order to learn about electronic structure, oxidation state, spin state, and local geometry. His David Rognlie Award Lecture is now online. He has applied these methods to study the protein dynamics of myoglobin, spin-crossover in iron(II) complexes, and molecular chirality in solution, demonstrating the broad applicability of the method.



The ACA History Project showcases and preserves the history of crystallography, X-ray diffraction, and structural science through online access, articles in ACA RefleXions quarterly magazine, and videos to our YouTube channel. 

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