Editing Crystallography (section)

== Methodology ==
{{Main|X-ray crystallography|Electron diffraction|Neutron crystallography|NMR crystallography}}

Crystallographic methods depend mainly on analysis of the [[diffraction]] patterns of a sample targeted by a beam of some type. [[X-ray]]s are most commonly used; other beams used include [[electron]]s or [[neutron]]s. Crystallographers often explicitly state the type of beam used, as in the terms ''[[X-ray diffraction]], [[neutron diffraction]]'' and ''[[electron diffraction]]''. These three types of radiation interact with the specimen in different ways.
* X-rays interact with the [[Electron density|spatial distribution of electrons]] in the sample.<ref>{{Cite book |last1=Cullity |first1=B. D.|title=Elements of X-ray diffraction |last2=Stock |first2=Stuart R. |date=2001 |publisher=Prentice Hall |isbn=978-0-201-61091-8 |edition=3rd |location=Upper Saddle River, NJ}}</ref>
* Neutrons are scattered by the atomic nuclei through the [[strong nuclear force]]s, but in addition the [[magnetic moment]] of neutrons is non-zero, so they are also scattered by [[magnetic field]]s. When neutrons are scattered from [[hydrogen]]-containing materials, they produce diffraction patterns with high noise levels, which can sometimes be resolved by substituting [[deuterium]] for hydrogen.<ref>{{Cite web |title=ISIS Neutron Diffraction with Isotopic Substitution |url=https://www.isis.stfc.ac.uk/Pages/Neutron-Diffraction-with-Isotopic-Substitution.aspx |access-date=2024-07-02 |website=www.isis.stfc.ac.uk |language=en-GB}}</ref>
* Electrons are [[charged particle]]s and therefore interact with the total [[Charge density|charge distribution]] of both the [[atomic nuclei]] and the electrons of the sample.<ref>{{Cite book |last=Cowley |first=John Maxwell |author-link=John Maxwell Cowley|title=Diffraction physics |date=1995 |publisher=Elsevier Science B.V |isbn=978-0-444-82218-5 |edition=3rd |series=North-Holland personal library |location=Amsterdam; New York}}</ref>{{Rp|location=Chpt 4}}
It is hard to focus x-rays or neutrons, but since electrons are charged they can be focused and are used in [[electron microscope]] to produce magnified images. There are many ways that [[transmission electron microscopy]] and related techniques such as [[scanning transmission electron microscopy]], [[high-resolution electron microscopy]] can be used to obtain images with in many cases atomic resolution from which crystallographic information can be obtained. There are also other methods such as [[low-energy electron diffraction]], [[low-energy electron microscopy]] and [[reflection high-energy electron diffraction]] which can be used to obtain crystallographic information about surfaces.