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Difference between revisions of "Systematic absences"

From Online Dictionary of Crystallography

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== See also ==
 
== See also ==
*[[reflection conditions]]<br>
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*[[reflection conditions]]
*Section 1.6.4 of ''International Tables of Crystallography, Volume A''<br>, 6<sup>th</sup> edition
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*Section 1.6.4 of ''International Tables of Crystallography, Volume A'', 6<sup>th</sup> edition
  
 
[[Category:X-rays]]<br>
 
[[Category:X-rays]]<br>

Revision as of 16:55, 11 April 2017

Absences systématiques (Fr). Extinciones sistemáticas (Sp). Assenze sistematiche, estinzioni sistematiche (It). 消滅則 (Ja)

Definition

One speaks of systematic absences or extinctions when the structure factor is zero, due either to the centring of the lattice or to the presence of glide or screw symmetry elements. Conversely, the conditions for a reflection to exist and not to be systematically absent, are called reflection conditions.

See also