Inspired by Eq. 5, we numerically investigated the relation between R • 2 values and total effective correlation times in MD simulations. Figure shows τ eff values and spin relaxation rates, R1, R • 2 and hetNOE, calculated separately for each residue from MD simulations of wide range of different protein systems, including globular and multi-domain proteins, as well as peptide-micelle complexes . Indeed, we observe practically linear relation between τ eff and R2, suggesting that only the first term in Eq. 5 is significant for all different types of proteins and peptides with different dynamic landscapes . Magnitudes of different terms in Eq. 5, shown in supplementary figure , reveal that linear term indeed dominates and non-linear terms have significant contribution only with timescales below approximately 3 ns. On the other hand, relations between τ eff and R1 or hetNOE values are more complicated in Fig. , revealing ambiguous relations between these parameters and N-H bond rotational dynamics. In addition, Fig. shows numerically solved lines from Eqs. 1-3 assuming that the N-H bond rotation is dictated by only one timescale, which then equals the total effective correlation time. Also, this approach, denoted here as a 1-timescale approximation, gives results close to simulations for R • 2 , while significant deviations are observed for R1 and hetNOE.