For both, AA and G-CG models, a number N η of production runs of 10 ns each were performed. For the AA model, N η = 6 for the least viscous systems (c PEG → 0), and N η = 20 for the most viscous systems (c PEG → 100). For the G-CG model, a larger number of runs were needed to achieve sufficient statistics due to reduced degrees of freedom as compared to the AA model. We used N η = 2000 ∀c PEG . For both AA and G-CG calculations, the mean values and standard deviations of the viscosities were calculated from the different runs.