The inter-molecule component R T 1 was calculated by performing the double summation in Eq. ( ) only between atom pairs belonging to different molecules. R T 1 typically provides information on the translational (T) motion of molecules . The inter-monomer component R R-chain 1 was calculated from atoms belonging to different monomers from the same molecule, and the intra-monomer component R R-bead 1 was calculated from atoms belonging to the same monomer. The letter R in R-chain and R-bead stands for rotational . While T and R-chain contributions are present within both AA and CoM-CG calculations, R-bead can only be calculated from an AA representation (Fig. ). Therefore, R R-bead 1 = 0 in Eq. ( ) in the case of CoM-CG calculations. , and R R-bead 1 were extracted from the AA calculations. For the sake of comparing AA to CoM-CG, contributions involving the water molecules were excluded from all calculations here. Our results show that, in the low PEG concentration limit, c PEG → 0, the intra-monomer contribution R R-bead 1 dominates over the two others, while in the high PEG concentration limit, R R-bead 1 and R T 1 are of similar magnitude and dominate over R R-chain 1 (Fig. ). As expected, the relative importance of R T 1 with respect to R R-bead 1 and R R-chain 1 significantly increases as c PEG increases, due to PEG-PEG interactions becoming more and more prominent at larger PEG concentration. Overall, our results obtained with the AA model show that R R-bead 1 is the dominant contribution to R 1 for all c PEG . Therefore the absence of the R R-bead 1 contribution from a CoM-CG representation explains, at least in part, the offset measured on the value of R 1 when performing CoM-CG NMR calculations (Fig. ).