Properties of the descriptive symbols

Fischer, W.; Koch, E.

doi:10.1107/97809553602060000531

International
Tables for
Crystallography
Volume A
Space-group symmetry
Edited by Th. Hahn

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International Tables for Crystallography (2006). Vol. A. ch. 14.2, p. 872

Section 14.2.3.4. Properties of the descriptive symbols

W. Fischer^a and E. Koch^a ^*

^a Institut für Mineralogie, Petrologie und Kristallographie, Philipps-Universität, D-35032 Marburg, Germany
Correspondence e-mail: kochelke@mailer.uni-marburg.de

14.2.3.4. Properties of the descriptive symbols

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Different kinds of relations between lattice complexes are brought out.

Examples

$[P \leftrightarrow P4x \leftrightarrow P4x2z, \quad I4xxx \leftrightarrow ..2\ I4xxx, \quad P4x \leftrightarrow I4x]$ .

In many cases, limiting-complex relations can be deduced from the symbols. This applies to limiting complexes due either to special metrical parameters (e.g. $[cP \leftrightarrow rP]$ etc.) or to special values of coordinates (e.g. both P4x and P4xx are limiting complexes of P4xy). If the site set consists of only one point, the central part of the symbol specifies all corresponding limiting complexes without degrees of freedom that are due to special values of the coordinates (e.g. $[2_{1}2_{1}]$ . $[FA_{a}B_{b}C_{c}I_{a}I_{b}I_{c}1xyz]$ for the general position of $[P2_{1}2_{1}2_{1}]$ ).

References

International Tables for Crystallography (2006). Vol. A. ch. 14.2, p. 872