Crystallography and physics

X-ray crystallography was initiated by physicists in the early 20th century. However—as is common with many developments in physics—the subject quickly moved beyond the confines of physics to produce key advances in chemistry, biology, mineralogy and materials science. This article discusses the role of physics in developing crystallography over the last 100 years and the relevance of crystallography to physics today. It is concluded that although crystallography has become somewhat hidden within physics departments it is still a key component of modern condensed matter physics. (invited comment)