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

C2 (5) Space Group

Table 1673. C2 (5) space group.

Name in the International Tables for Crystallography
C2 C
12 2
Crystal system
Monoclinic 2/m
Asymm
0 ≤ x ≤ 1/2 and 0 ≤ y ≤ 1/2 and 0 ≤ z ≤ 1
4 Absence of reflections

 

Translation
 
Symmetry (atomic coordinates)
X, Y, Z; -X, Y, -Z; 1/2+X, 1/2+Y, Z; 1/2-X, 1/2+Y, -Z
Forbidden reflections The three space groups C2/m, C2 and Cm have the same systematic forbidden reflections which are caused by the C-centering (h+k = 2n+1). The other symmetry operations in the three space groups, e.g. 2-fold rotation axis (2) and mirror plane (m) in the C2/m space group, do not cause forbidden reflections.
Crystal examples