Editing X-ray crystallography (section)

===Materials science and mineralogy===
[[File:PIA16217-MarsCuriosityRover-1stXRayView-20121017.jpg|thumb|upright|left|First X-ray diffraction view of [[Martian soil]] – [[CheMin|CheMin analysis]] reveals [[feldspar]], [[pyroxenes]], [[olivine]] and more ([[Curiosity rover]] at "[[Rocknest (Mars)|Rocknest]]", October 17, 2012).<ref name="NASA-20121030" />]]
The application of X-ray crystallography to [[mineralogy]] began with the structure of [[garnet]], which was determined in 1924 by Menzer. A systematic X-ray crystallographic study of the [[silicate]]s was undertaken in the 1920s. This study showed that, as the [[silicon|Si]]/[[oxygen|O]] ratio is altered, the silicate crystals exhibit significant changes in their atomic arrangements. Machatschki extended these insights to minerals in which aluminium substitutes for the [[silicon]] atoms of the silicates. The first application of X-ray crystallography to [[metallurgy]] also occurred in the mid-1920s.<ref>{{cite journal| vauthors = Westgren A, Phragmén G |date=1925|title=X-ray Analysis of the Cu-Zn, Ag-Zn and Au-Zn Alloys|journal=Phil. Mag. |volume=50 |page=311 |doi=10.1080/14786442508634742}}</ref><ref>{{cite journal| vauthors = Bradley AJ, Thewlis J |date=1926 |title=The structure of γ-Brass|journal= Proc. R. Soc. Lond. |volume=112 |page=678 |doi=10.1098/rspa.1926.0134 |issue=762 |bibcode=1926RSPSA.112..678B |doi-access=free}}</ref><ref>{{cite journal| vauthors = Hume-Rothery W|date=1926|title=Researches on the Nature, Properties and Conditions of Formation of Intermetallic Compounds (with special Reference to certain Compounds of Tin)|journal=Journal of the Institute of Metals|volume=35|page=295}}</ref><ref>{{cite journal| vauthors = Bradley AJ, Gregory CH |date=1927|title=The Structure of certain Ternary Alloys|doi=10.1038/120678a0|journal=Nature|volume=120|page=678|issue=3027|bibcode = 1927Natur.120..678. |doi-access=free}}</ref><ref>{{cite journal| vauthors = Westgren A|date=1932|title=Zur Chemie der Legierungen|journal=Angewandte Chemie |volume=45|page=33|doi=10.1002/ange.19320450202|issue=2|bibcode=1932AngCh..45...33W}}</ref><ref>{{cite journal| vauthors = Bernal JD|author-link=John Desmond Bernal|date=1935|title=The Electron Theory of Metals|journal=Annual Reports on the Progress of Chemistry|volume=32|page=181|doi=10.1039/AR9353200181}}</ref> Most notably, [[Linus Pauling]]'s structure of the alloy Mg<sub>2</sub>Sn<ref>{{cite journal| vauthors = Pauling L|title=The Crystal Structure of Magnesium Stannide|journal=J. Am. Chem. Soc.|volume=45|page=2777|doi=10.1021/ja01665a001|date=1923|issue=12}}</ref> led to his theory of the stability and structure of complex ionic crystals.<ref>{{cite journal| vauthors = Pauling L|title=The Principles Determining the Structure of Complex Ionic Crystals|journal=J. Am. Chem. Soc.|volume=51|page=1010|doi=10.1021/ja01379a006|date=1929|issue=4}}</ref> Many complicated [[inorganic]] and [[organometallic]] systems have been analyzed using single-crystal methods, such as [[fullerene]]s, [[porphyrin|metalloporphyrins]], and other complicated compounds. Single-crystal diffraction is also used in the [[pharmaceutical industry]]. The [[Cambridge Structural Database]] contains over 1,000,000 structures as of June 2019; most of these structures were determined by X-ray crystallography.<ref>{{Cite web |title=The Cambridge Structural Database {{!}} CCDC |url=https://www.ccdc.cam.ac.uk/solutions/software/csd/ |access-date=2024-05-07 |website=www.ccdc.cam.ac.uk |archive-date=2024-05-07 |archive-url=https://web.archive.org/web/20240507084044/https://www.ccdc.cam.ac.uk/solutions/software/csd/ |url-status=live }}</ref>

On October 17, 2012, the [[Curiosity rover]] on the [[Mars|planet Mars]] at "[[Rocknest (Mars)|Rocknest]]" performed the first X-ray diffraction analysis of [[Martian soil]]. The results from the rover's [[CheMin|CheMin analyzer]] revealed the presence of several minerals, including [[feldspar]], [[pyroxenes]] and [[olivine]], and suggested that the Martian soil in the sample was similar to the "weathered [[Basalt|basaltic soils]]" of [[Hawaii Volcanoes|Hawaiian volcanoes]].<ref name="NASA-20121030">{{cite web |vauthors=Brown D |title=NASA Rover's First Soil Studies Help Fingerprint Martian Minerals |url=http://www.nasa.gov/home/hqnews/2012/oct/HQ_12-383_Curiosity_CheMin.html |date=October 30, 2012 |publisher=[[NASA]] |access-date=October 31, 2012 |archive-date=June 3, 2016 |archive-url=https://web.archive.org/web/20160603091908/http://www.nasa.gov/home/hqnews/2012/oct/HQ_12-383_Curiosity_CheMin.html |url-status=dead }}</ref>

[[File:penicillin.png|thumb|The three-dimensional structure of [[penicillin]], solved by [[Dorothy Crowfoot Hodgkin]] in 1945. The green, red, yellow and blue spheres represent atoms of [[carbon]], [[oxygen]], [[sulfur]] and [[nitrogen]], respectively. The white spheres represent [[hydrogen]], which were determined mathematically rather than by the X-ray analysis.]]