Computer simulation studies of anisotropic systems. The density and temperature dependence of the second rank orientational order parameter for the nematic phase of a Gay Berne liquid crystal

Abstract The relative importance of anisotropic repulsive and attractive forces in stabilising a nematic liquid crystal may be assessed from the thermodynamic parameter Γ =−( ∂ ln T / ∂ ln V ) 〈 P 2 〉 , where 〈 P 2 〉 is the second rank orientational order parameter. A previous attempt to determine this quantity for the nematic phase of a Gay–Berne system has given a value about twice as large as that found experimentally. Here we report the determination of Γ from an extensive simulation study for a Gay–Berne system with parameters more appropriate for mesogenic molecules than those selected originally.