COMPUTER SIMULATION STUDY OF A NEMATOGENIC LATTICE MODEL BASED ON THE NEHRING–SAUPE INTERACTION POTENTIAL

Abstract

By now, nematogenic lattice models have been extensively studied in the literature; they usually involve cylindrically symmetric (uniaxial) particles and isotropic interaction potentials defined by even functions of the scalar products between unit vectors defining their orientations; anisotropic interaction potentials involving other scalar invariants, i.e. also depending on the orientations of the two particles with respect to the intermolecular vector, have been considered far less often. A model of the latter kind was proposed by Nehring and Saupe over 25 years ago; we have considered here its restriction to nearest neighbours, having the form [Formula: see text] Here the three-component vectors xj∈ Z3define centre-of-mass coordinates of the particles, and ukare three-component unit vectors defining their orientations; ∊ is a positive quantity setting energy and temperature scales (i.e. T*=kBT/∊); this model is seen to be the anisotropic counterpart to the generic Lebwohl–Lasher lattice model.The model has been addressed by simulation; comparisons are reported with other anisotropic lattice models recently studied in the literature.