Systematic absences

From Online Dictionary of Crystallography

Revision as of 12:01, 17 May 2017 by BrianMcMahon (talk | contribs) (Style edits to align with printed edition)

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


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