Difference between revisions of "Ogdohedry"
From Online Dictionary of Crystallography
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| − | <font color="blue">Ogdoédrie </font>(''Fr''). < | + | <font color="blue">Ogdoédrie</font> (''Fr''). <font color="red">Ogdoedrie</font> (''Ge''). <font color="black">Ogdoedria</font> (''It''). <font color="purple">八面像</font>(''Ja''). <font color="green">Ogdoedría</font> (''Sp''). |
Latest revision as of 13:17, 16 November 2017
Ogdoédrie (Fr). Ogdoedrie (Ge). Ogdoedria (It). 八面像(Ja). Ogdoedría (Sp).
Definition
The point group of a crystal is called ogdohedry if it is a subgroup of index 8 of the point group of its lattice.
In three-dimensional space there is only one ogdohedry: it corresponds to the geometric crystal class 3 of crystals belonging to the hexagonal lattice system (in the case of rhombohedral crystals, it corresponds instead to a tetartohedry).
See also
- Merohedry
- Tetartohedry
- Chapter 3.2.1 of International Tables for Crystallography, Volume A, 6th edition