InternationalMathematical, physical and chemical tablesTables for Crystallography Volume C Edited by E. Prince © International Union of Crystallography 2006 |
International Tables for Crystallography (2006). Vol. C, ch. 1.4, pp. 15-22
https://doi.org/10.1107/97809553602060000575 |

## Footnotes

^{‡}Deceased.

^{1}Here and in Chapter 9.7 , it is convenient to use the `short' symbols

*mm*, 32, 3

*m*, , , and instead of

*mm*2, 321,

*etc*., whenever it is desired to emphasize that no implication about orientation is intended.

^{2}In the arithmetic crystal class 2

*mmC*, two conventions concerning the nomenclature of axes conflict. The first is that, if only one face of the Bravais lattice is centred, the

*c*axis is chosen perpendicular to that face. The second is that, if there is one axis of symmetry uniquely different from any others, that axis is to be chosen as

*b*in the monoclinic system and as

*c*in the remaining systems. The second convention is usually regarded as the more important, and the `standard setting' of 2

*mmC*is

*mm*2

*A*. Both settings are listed in Table 1.4.2.1.

^{3}Three examples of informative definitions are: