Transport coefficients of soft sphere fluid at high densities

Molecular dynamics computer simulation has been used to compute in wide pressure–temperature region the self-diffusion coefficient and shear viscosity of soft-sphere fluids, in which the particles interact through the inverse power pair potential. The limitations of the previous empirical approaches and models for the description of the kinetic coefficients is shown. On the basis of the simulations the universal functions for diffusion coefficient and shear viscosity of soft spheres are constructed which allow to compute these quantities for any density and temperature. We show that the behavior of shear viscosity at high temperatures is more complex than the one of diffusion coefficient and give quantitative explanation of this result.