Ordered states of a nematic liquid

The interaction employed in the Maier-Saupe theory of the nematic state is generalized in a manner consistent with the asymmetry of the molecules that exhibit such a phase. In the molecular field approximation such an interaction then yields a first-order transition from the isotropic to a uniaxial state followed, at lower temperatures, by a second-order transition to a biaxial state. © 1970 The American Physical Society.