Brownian dynamics of hard spherocylinders
A model of hard spherocylinders exhibiting Brownian dynamics in a solvent is investigated by Brownian dynamics simulations. Long-time translational and rotational self-diffusion coefficients are calculated in the disordered phase over the whole range of densities and a ratio p of total length to width ranging from 1 to 6. A simple analytical formula is given to fit the results. The self-diffusion coefficients are also obtained along the fluid freezing line for arbitrary p. Measured in terms of their short-time limits, both self-diffusion coefficients are nonmonotonic in p. For 2≤p≤6, the long-time to short-time rotational self-diffusion ratio is about 0.12, which constitutes a simple dynamical phase transition rule for the fluid-nematic and fluid-crystalline transition.