ABSTRACT
Liquid crystals (LCs) are liquid or liquid-like states that are anisotropic. Therefore, they have less symmetry than ordinary liquids, but higher symmetry than crystals. The anisotropy makes them optically birefringent like most crystals. This entry relates the structural properties of the organic molecules that are the building blocks to the optical and the electro-optic properties of the different LC phases. The exceptional elastic properties of LCs are also described.
