Tables for
Volume D
Physical properties of crystals
Edited by A. Authier

International Tables for Crystallography (2006). Vol. D, ch. 1.1, pp. 20-21

Section Trigonal system

A. Authiera*

aInstitut de Minéralogie et de la Physique des Milieux Condensés, Bâtiment 7, 140 rue de Lourmel, 75015 Paris, France
Correspondence e-mail: Trigonal system

| top | pdf | Groups [3] and [{\bar 3}]

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The reduction is first applied in the system of axes tied to the eigenvectors of the operator representing a threefold axis. The system of axes is then changed to a system of orthonormal axes with [Ox_{3}] parallel to the threefold axis: [Scheme scheme103] with [\left. \matrix{t_{1111} - t_{1122} = &t_{1212} + t_{1221}\cr t_{1112} + t_{1121} = &- (t_{1211} + t_{2111}).\cr}\right\}]

There are 27 independent components. Groups [{\bar 3}m], [32], [3m], with the twofold axis parallel to [Ox_{1}]

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[Scheme scheme104] with [t_{1111} - t_{1122} = t_{1212} + t_{1221}.]

There are 14 independent components.

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