crystal class

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Related to Crystallographic point group: Space groups

crystal class

[′krist·əl ′klas]
(crystallography)
One of 32 categories of crystals according to the inversions, rotations about an axis, reflections, and combinations of these which leaves the crystal invariant. Also known as symmetry class.
References in periodicals archive ?
With reference to the derivation of .Krishna Murthy and Gopala Kishnamurthy [7], we can associate the ferroic species of quasi crystals whose ferroic point group is the sub group of order two of the prototypic point group and these non total symmetric one dimensional alternating representation of a non crystallographic point group (quasi crystal) not only induce the ferroic species associated with the point group but also gives the number of constants required to describe any physical property for the induced ferroic species.
20 out of 32 crystallographic point groups are piezoelectric).The very basis of functional biological systems is electromechanics--from nerve-controlled muscle contraction on the macroscale, to cardiac activity and hearing on the micron scale, to energy storage in mitochondria, voltage-controlled ion channels, and electromotor proteins on the nanoscale.
Wachtman Jr., Reduction of Crystallographic Point Groups to Subgroups by Homogeneous Stress, J.