International
Tables for Crystallography Volume E Subperiodic groups Edited by V. Kopský and D. B. Litvin © International Union of Crystallography 2006 |
International Tables for Crystallography (2006). Vol. E, ch. 1.2, pp. 13-14
Section 1.2.7. Origin^{a}Department of Physics, University of the South Pacific, Suva, Fiji, and Institute of Physics, The Academy of Sciences of the Czech Republic, Na Slovance 2, PO Box 24, 180 40 Prague 8, Czech Republic, and ^{b}Department of Physics, Penn State Berks Campus, The Pennsylvania State University, PO Box 7009, Reading, PA 19610-6009, USA |
The origin has been chosen according to the following conventions:
Origin statement: In the line Origin immediately below the diagrams, the site symmetry of the origin is stated if different from the identity. A further symbol indicates all symmetry elements that pass through the origin. For the three layer groups p4/n (L52), p4/nbm (L62) and p4/nmm (L64) where the origin is on the fourfold axis, the statement `at from centre' is given to denote the position of the origin with respect to an inversion centre.