Antinematic orientational order produced by an extreme case of the generalized Straley lattice model

We address here a special, extreme case of the quadratic pair interaction potential between classical, D2h-symmetric particles (the generalized Straley model) on a three-dimensional simple cubic lattice. The model involves predominant antinematic couplings and it has been studied by Monte Carlo simulation and a molecular field treatment. The obtained results show a second-order transition between the isotropic phase and the low-temperature one, exhibiting uniaxial antinematic order.