**Authors:** Eckhard Hitzer, Christian Perwass

A new interactive software tool is described, that visualizes 3D space group
symmetries. The software computes with Clifford (geometric) algebra. The space group
visualizer (SGV) originated as a script for the open source visual CLUCalc, which fully
supports geometric algebra computation.
Selected generators (Hestenes and Holt, JMP, 2007) form a multivector generator
basis of each space group. The approach corresponds to an algebraic implementation
of groups generated by reflections (Coxeter and Moser, 4th ed., 1980). The basic
operation is the reflection. Two reflections at non-parallel planes yield a rotation, two
reflections at parallel planes a translation, etc. Combination of reflections corresponds
to the geometric product of vectors describing the individual reflection planes.
We first give some insights into the Clifford geometric algebra description of
space groups. We relate the choice of symmetry vectors and the origin of cells in the
geometric algebra description and its implementation in the SGV to the conventional
crystal cell choices in the International Tables of Crystallography (T. Hahn, Springer,
2005). Finally we briefly explain how to use the SGV beginning with space group
selection. The interactive computer graphics can be used to fully understand how reflections
combine to generate all 230 three-dimensional space groups.
**Mathematics Subject Classification (2000).** Primary 20H15; Secondary 15A66, 74N05,
76M27, 20F55 .
**Keywords.** Clifford geometric algebra, interactive software, space groups, crystallography,
visualization.

**Comments:** 27 Pages. 21 figures, 14 tables. Adv. Appl. Clifford Alg., Vol. 20(3-4), pp. 631–658, (2010), DOI 10.1007/s00006-010-0214-z

**Download:** **PDF**

[v1] 2013-06-18 22:51:41

**Unique-IP document downloads:** 196 times

Vixra.org is a pre-print repository rather than a journal. Articles hosted may not yet have been verified by peer-review and should be treated as preliminary. In particular, anything that appears to include financial or legal advice or proposed medical treatments should be treated with due caution. Vixra.org will not be responsible for any consequences of actions that result from any form of use of any documents on this website.

**Add your own feedback and questions here:**

*You are equally welcome to be positive or negative about any paper but please be polite. If you are being critical you must mention at least one specific error, otherwise your comment will be deleted as unhelpful. *