Accuracies of linear and 1-timescale approximations to determine τ eff values directly from R • 2 values are quantified against simulation data in supplementary Figs. and. Linear approximation systematically overestimates τ eff values, particularly for low fields (up to 1.5 ns for 400 MHz, less than 0.5 ns for fields above 600 MHz) and residues with fast timescales below approximately 3 ns (Fig. ). 1-timescale approximation has a slight tendency to underestimate τ eff values, but it can be considered to be slightly more accurate than the linear approximation, particularly for residues with rapid rotations (Fig. b and supplementary Figs. and).