P4/mbm (127) space group

P4/mbm (127) Space Group
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Table 1541a. P4/mbm (127) space group.

Name in the International Tables for Crystallography	P4/mbm	Lattice type	P
Patterson space group	123	Point group	4/mmm
Crystal system	Tetragonal	Laue class	4/mmm
Asymm	0 ≤ x ≤ 1/2 and 0 ≤ y ≤ 1/2 and 0 ≤ z ≤ 1/2 and y ≤ 1/2-x
Number of symmetry operators	16	Absence of reflections
Translation
Symmetry (atomic coordinates)	X, Y, Z; -X, -Y, Z; -Y, X, Z; Y, -X, Z; 1/2-X, 1/2+Y, -Z; 1/2+X, 1/2-Y, -Z; 1/2+Y, 1/2+X, -Z; 1/2-Y, 1/2-X, -Z; -X, -Y, -Z; X, Y, -Z; Y, -X, -Z; -Y, X, -Z; 1/2+X, 1/2-Y, Z; 1/2-X, 1/2+Y, Z; 1/2-Y, 1/2-X, Z; 1/2+Y, 1/2+X, Z
Crystal examples

Table 1541b. C4/mmb (127) space group.

Name in the International Tables for Crystallography	C4/mmb (D_4h⁵)	Lattice type
Patterson space group		Point group
Crystal system	Tetragonal	Laue class
Asymm
Number of symmetry operators		Absence of reflections
Translation
Symmetry (atomic coordinates)
Remarks	The unit-cell axes double only along a and b, and thus in electron diffraction pattern, half-integral reflections are found for h and k, but with l integral. For distorted perovskites, the adjacent octahedra along the c-axis are rotated in inphase (+) manner.
Crystal examples	NaNbO₃, CsCaCl₃ and CsPbCl₃.

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