How to calculate shear viscosity of polymers using dpd module?

Hello everyone,

I am trying to run a dpd simulation of Polymer solutions using DPD module of materials studio to calculate the shear viscosity. Through literature survey, I found that it is calculated using the formula shear viscosity=tau(xz)/shear rate(in x direction). The values that i am getting is nearly 10 times less than the experimental value but I dont know why. The parameters that I used has been taken from a paper.

Also, I tried doing the same using Mesocite module but still the answers that I get is 100 times lesser than the experimental values. Can i know how to rectify the above simulated value??