An atomistic description of the nematic and smectic phases of 4-n-octyl-4′ cyanobiphenyl (8CB)

We report the results of atomistic molecular dynamics simulations of 4-n-octyl-4' cyanobiphenyl (8CB) on samples of 750 and 3000 molecules showing the spontaneous formation of the nematic phase and then of smectic layers by gradually cooling down from the isotropic phase. Orientational, positional, and mixed order parameters, layer spacing, translational diffusion tensor components and their temperature dependence are reported. A detailed comparison with available experimental data validates the model and force field employed and clarifies the molecular organization of this important liquid crystal often used as reference smectic material.