SIMULATION OF STRUCTURE AND DYNAMICS NEAR THE ISOTROPIC-NEMATIC TRANSITION

We present a computer simulation study of orientational correlations i n a molecular liquid approaching the isotropic-nematic transition, inc luding the first calculation of the direct correlation function c(1,2) in this regime. While the second-rank orientational correlation lengt h diverges, the associated component of c(1,2) remains short ranged, a nd its spatial integral approaches the mechanical instability limit fo r the isotropic phase as predicted by density-functional theory. Orien tational correlation lengths and times are quite well described by Lan dau-de Gennes theory.