G-CG calculations of R 1 were done assuming that each bead carries an effective number of spins n eff , where n eff was chosen such that the total number of spins per PEG molecule is the same as for the AA model. For PEG molecules with molar mass M PEG = 200 g/mol, each end contains 3 hydrogen atoms, and each central monomer contains 4 hydrogen atoms (Fig. ), so n eff = (2 × 3 + 3 × 4)/5 = 3.6. For G-CG models, the autocorrelation function (Eq. ( )) was modified as follows: