It is possible to calculate the viscosity using the SLLOD equations of motion together with the Nosé-Hoover thermostat. Then the viscosity is obtained as the ratio of the shear stress and the velocity gradient. Note, however, that you get the viscosity in the non-Newtronian regime. You have to go down to very low shear rates to get the viscosity in the Newtonian regime that should be the same one as the one that you obtain by using the Green-Kubo relations.

When you apply the Lees-Edwards boundary conditions you simulate homogeneous system and there are no wall effects. If you want to know more about the SLLOD equations you can read the book Statistical Mechanics of Nonequilibrium Liquids, Academic Press, London, 1990, by D. J. Evans and G. P. Morriss.

However, if you want to simulate shear banding you must realise that this is a nonequilibrium system. If you use the SLLOD equations the results will depend on the implementation of the thermostat.It is not possible to use Green-Kubo relations because they only work close to equilibrium. There are more appropriate thermostats but they cannot be used in Lammps. I can send you the references if you want. If you have other questions on shear flow simulations, feel free to ask.

Best Regards,

Sten Sarman

Den Thu, 8 Oct 2015 16:11:27 -0400, Salomon Turgman Cohen <sturgman@…29…> skrev: