Many body forces between long conducting molecules

Non-equilibrium molecular dynamics is used to calculate the wavevector and strain rate dependence of shear viscosity in a soft sphere fluid. The calculations are consistent with a non-analytic functional dependence of viscosity with wavevector. A consequence of such non-analyticity would be that the linear and non-linear Burnett coefficients for viscosity would not exist for fluids in three dimensions. The calculations also show the numerical consistency of three different non-equilibrium simulation methods for calculating shear viscosity.