Practical Electron Microscopy and Database

An Online Book, Second Edition by Dr. Yougui Liao (2006)

Practical Electron Microscopy and Database - An Online Book

Chapter/Index: Introduction | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Appendix

Pm-3m (221) Space Group

Table 3010a. Pm-3m (221) space group.

Name in the International Tables for Crystallography	Pm-3m	Lattice type	P
Patterson space group	221	Point group	m-3m
Crystal system	Cubic	Laue class	m-3m
Asymm	0 ≤ x ≤ 1/2 and 0 ≤ y ≤ 1/2 and 0 ≤ z ≤ 1/2 and y ≤ x and z ≤ y
Number of symmetry operators	48
Symmetry (atomic coordinates)	X, Y, Z; -X, -Y, Z; -X, Y, -Z; X, -Y, -Z; Z, X, Y; Z, -X, -Y; -Z, -X, Y; -Z, X, -Y; Y, Z, X; -Y, Z, -X; Y, -Z, -X; -Y, -Z, X; Y, X, -Z; -Y, -X, -Z; Y, -X, Z; -Y, X, Z; X, Z, -Y; -X, Z, Y; -X, -Z, -Y; X, -Z, Y; Z, Y, -X; Z, -Y, X; -Z, Y, X; -Z, -Y, -X; -X, -Y, -Z; X, Y, -Z; X, -Y, Z; -X, Y, Z; -Z, -X, -Y; -Z, X, Y; Z, X, -Y; Z, -X, Y; -Y, -Z, -X; Y, -Z, X; -Y, Z, X; Y, Z, -X; -Y, -X, Z; Y, X, Z; -Y, X, -Z; Y, -X, -Z; -X, -Z, Y; X, -Z, -Y; X, Z, Y; -X, Z, -Y; -Z, -Y, X; -Z, Y, -X; Z, -Y, -X; Z, Y, X
Crystal examples	CsI, CsBr. CsCl: Cs at 0, 0, 0 and Cl at 1/2, 1/2, 1/2. ReO₃ (Rhenium oxide): Re at 0, 0, 0 and O at 1/2, 0, 0. CaTiO₃: Ti at 0, 0, 0; Ca at 1/2, 1/2, 1/2 and O at 1/2, 0, 0. AuCu₃: Au at 0, 0, 0 and Cu at 0, 1/2, 1/2.

Table 3010b. Example of compounds with similar structures to BCC.

	BCC	TiO₂ (Rutile)	CsCl	Cu₂O (Cuprite)
Space group	Im-3m	P42/mnm	Pm-3m	Pn-3m
Compounds	α-Fe, W, Nb, Ta, Na, K, Mo, V	GeO₂, SnO₂, PbO₂	CsI, CsBr, CsCl	Pb₂O, Ag₂O