Hydrodynamic theories of relaxation in liquids

Molecular hydrodynamics is used to theoretically describe recent computer experiments on rough and partially rough sphere fluids. The long time behavior of hydrodynamic AVCF (angular velocity correlation function) is discussed. A theory of coupled translational and rotational relaxation in solution including the effects of hydrodynamic interaction is presented. The translational, translational-rotational diffusion tensors are computed using the method of hydrodynamic reflections. Time correlation functions are found from a coupled translational-rotational diffusion equation. The concentration dependence of rotational diffusion coefficients is calculated and compared with experiment data. The effect of many body hydrodynamic interactions is briefly considered.