Actions

Difference between revisions of "Systematic absences"

From Online Dictionary of Crystallography

m (Style edits to align with printed edition)
(Added German and Spanish translations (U. Mueller))
 
Line 1: Line 1:
<Font color="blue">Absences systématiques</Font> (''Fr''). <Font color="green"> Extinciones sistemáticas </Font> (''Sp''). <Font color="black">Assenze sistematiche, estinzioni sistematiche </Font>(''It''). <Font color="purple">消滅則</Font> (''Ja'').
+
<font color="blue">Absences systématiques</font> (''Fr''). <font color="red">Systematische Auslöschungen</font> (''Ge''). <font color="black">Assenze sistematiche, estinzioni sistematiche</font>(''It''). <font color="purple">消滅則</font> (''Ja''). <font color="green">Ausencias sistemáticas, extinciones sistemáticas</font> (''Sp'').
  
 
== Definition ==
 
== Definition ==

Latest revision as of 09:22, 20 November 2017

Absences systématiques (Fr). Systematische Auslöschungen (Ge). Assenze sistematiche, estinzioni sistematiche(It). 消滅則 (Ja). Ausencias sistemáticas, extinciones sistemáticas (Sp).

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