No translational order — Nematics

The nematic liquid crystal, N phase, is the only liquid crystal phase without any long range translational order. Nematics are the most important member in the family of the liquid crystals and are widely used in the display industry. 

In nematics, the molecules tend to be parallel to each other. The preferred direction of parallel orientation is characterized by the director, 

This phase has a symmetrical axis Coo along the director. In addition, there is a reflection-symmetry plane perpendicular to the axis 6T and a mirror-symmetry plane through the Coo axis. Therefore, the local symmetry of nematics can be expressed by the D.-. h group. Of course, nematics have three dimensional translational symmetry. 

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