Difference between revisions of "Systematic absences"
From Online Dictionary of Crystallography
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Sections 2.2.13 and 12.3.5 of ''International Tables of Crystallography, Volume A''<br> | Sections 2.2.13 and 12.3.5 of ''International Tables of Crystallography, Volume A''<br> | ||
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Revision as of 11:30, 8 February 2012
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
reflection conditions
Sections 2.2.13 and 12.3.5 of International Tables of Crystallography, Volume A