Difference between revisions of "Geometric crystal class"
From Online Dictionary of Crystallography
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| − | + | <font color="blue">Classes cristallines géométriques</font> (''Fr''); <font color="red">Geometrische Kristallklasse</font> (''Ge''); <font color="green">Clases cristallinas geométricas</font> (''Sp''); <Font color="black"> Classi cristalline geometriche </Font>(''It''). | |
Revision as of 15:32, 23 February 2007
Classes cristallines géométriques (Fr); Geometrische Kristallklasse (Ge); Clases cristallinas geométricas (Sp); Classi cristalline geometriche (It).
Definition
Geometric crystal classes (or simply 'crystal classes') classify the symmetry groups of the external shape of macroscopic crystals, namely according to the morphological symmetry. There are 10 two-dimensional geometric crystal classes and 32 three-dimensional geometric crystal classes, in one to one correspondence with the 10 and 32 point groups in E2 and E3, respectively.
See also
Section 8.2.4 of International Tables of Crystallography, Volume A