Computer simulation study of a biaxial nematogenic lattice model associated with a three-dimensional lattice and involving dispersion interactions

The present paper considers a biaxial nematogenic lattice model, involving particles of D-2/i, symmetry, whose centres of mass are associated with a three-dimensional simple-cubic lattice; the pair potential is defined by a London-De Boer-Heller dispersion interaction, restricted to nearest neighbours; to the best of our knowledge, this model has not previously been studied by simulation. On the other hand, upon isotropically averaging over the intermolecular unit vector, another interaction model is obtained (which, in turn, can be introduced in other ways and guises as well), extensively studied by Mean Field treatment and Monte Carlo simulation. We present here Monte Carlo simulation results, showing mild but recognizable differences between the two models, actually equivalent at Mean Field level. (C) 2004 Elsevier B.V. All rights reserved.