MOLECULAR-DYNAMICS SIMULATION OF A LIQUID-CRYSTALLINE MIXTURE

We present results from a molecular dynamics simulation of benzene dis solved in the mesogen 4-n-pentyl-4'-cyanobiphenyl (5CB). The computer simulation is based on a realistic atom-atom potential and is performe d in the nematic phase. Singlet orientational distribution functions a re reconstructed from order parameters employing several methods, and the estimated distributions are compared with those obtained directly from the trajectory. Transport properties have been studied by calcula ting translational diffusion coefficients in directions both parallel and perpendicular to the liquid crystalline director. The simulated di ffusion coefficients were found to be of the same order of magnitude a s those measured in experiments. Second rank orientational time correl ation functions are used to investigate molecular reorientations and s ignificant deviations from the small step rotational diffusion model a re established. Molecular structure and internal dynamics of 5CB have been examined by correlating the time dependence of dihedral angles wi th effective torsional potentials. (C) 1997 American Institute of Phys ics.