Integral reflection conditions

From Online Dictionary of Crystallography

Conditions de réflexion intégrales (Fr).

Definition

The integral reflections are the general reflection conditions due to the centring of cells. They are given in the table below:

Integral reflection conditions for centred lattices.

Reflection condition	Centring type of cell	Centring symbol
None	Primitive	P R (rhombohedral axes)
h + k = 2n	C-face centred	C
k + l = 2n	A-face centred	A
l + h = 2n	B-face centred	B
h + k + l = 2n	body centred	I
h + k, h + l and k + l = 2n or: h, k, l all odd or all even (‘unmixed’)	all-face centred	F
− h + k + l = 3n	rhombohedrally centred, reverse setting	R (hexagonal axes)
h − k + l = 3n	rhombohedrally centred, obverse setting (standard)
h − k = 3n	hexagonally centred	H

See also

Section 2.2.13.1 of International Tables of Crystallography, Volume A

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