Practical Electron Microscopy and Database

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

I4/mmm (139) Space Group

Table 3000. I4/mmm (139) space group. Name in the International Tables for Crystallography I4/mmm Lattice type I Patterson space group 139 Point group 4/mmm Crystal system Tetragonal Laue class 4/mmm Asymm 0 ≤ x ≤ 1/2 and 0 ≤ y ≤ 1/2 and 0 ≤ z ≤ 1/4 and x ≤ y Number of symmetry operators 32 Symmetry (atomic coordinates) X, Y, Z; -X, -Y, Z; -Y, X, Z; Y, -X, Z; -X, Y, -Z; X, -Y, -Z; Y, X, -Z; -Y, -X, -Z; -X, -Y, -Z; X, Y, -Z; Y, -X, -Z; -Y, X, -Z; X, -Y, Z; -X, Y, Z; -Y, -X, Z; Y, X, Z; 1/2+X, 1/2+Y, 1/2+Z; 1/2-X, 1/2-Y, 1/2+Z; 1/2-Y, 1/2+X, 1/2+Z; 1/2+Y, 1/2-X, 1/2+Z; 1/2-X, 1/2+Y, 1/2-Z; 1/2+X, 1/2-Y, 1/2-Z; 1/2+Y, 1/2+X, 1/2-Z; 1/2-Y, 1/2-X, 1/2-Z; 1/2-X, 1/2-Y, 1/2-Z; 1/2+X, 1/2+Y, 1/2-Z; 1/2+Y, 1/2-X, 1/2-Z; 1/2-Y, 1/2+X, 1/2-Z; 1/2+X, 1/2-Y, 1/2+Z; 1/2-X, 1/2+Y, 1/2+Z; 1/2-Y, 1/2-X, 1/2+Z; 1/2+Y, 1/2+X, 1/2+Z Crystal examples MoSi2: Mo at 0, 0, 0 and Si at 0, 0, 1/3. Nb4N3, Bi2.2Sr0.8Nb1.9Sc0.1O9   [100] Zr41Ti14Cu12.5Ni10Be22.5. (a = 0.34 nm, and c = 1.137 nm) [1] Figure 3000. Examples of indexed electron diffraction (or FFT) patterns of I4/mmm (139) crystals.       [1] Q. Wei, N. Wanderka, P. Schubert-Bischoff, and M-P. Macht, S. Friedrich, Crystallization phases of the Zr41Ti14Cu12.5Ni10Be22.5 alloy after slow solidification, J. Mater. Res., 15 (8) 1729, (2000).