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

mm2 Point Group

Point group mm2 belongs to orthorhombic lattices (see Table 2980). As indicated in page1592, mm2 denotes mirrors normal to x and y axes with a two-fold axis along z axis.

Table 2980. All space groups which have point group mm2.
Space Group Patterson Space Group Number of Symmetry Operators Crystal System Laue Class Lattice Type
Pmm2 47 4 Orthorhombic mmm P
Pmc21 47 4 Orthorhombic mmm P
Pcc2 47 4 Orthorhombic mmm P
Pma2 47 4 Orthorhombic mmm P
Pca21 47 4 Orthorhombic mmm P
Pnc2 47 4 Orthorhombic mmm P
Pmn21 47 4 Orthorhombic mmm P
Pba2 47 4 Orthorhombic mmm P
Pna21 47 4 Orthorhombic mmm P
Pnn2 47 4 Orthorhombic mmm P
Cmm2 65 8 Orthorhombic mmm C
Cmc21 65 8 Orthorhombic mmm C
Ccc2 65 8 Orthorhombic mmm C
Amm2 65 8 Orthorhombic mmm A
Abm2 65 8 Orthorhombic mmm A
Ama2 65 8 Orthorhombic mmm A
Aba2 65 8 Orthorhombic mmm A
Fmm2 69 16 Orthorhombic mmm F
Fdd2 69 16 Orthorhombic mmm F
Imm2 71 8 Orthorhombic mmm I
Iba2 71 8 Orthorhombic mmm I
Ima2 71 8 Orthorhombic mmm I