Figure 2.

Effective correlation times τ_eff (top) and spin–lattice relaxation rates R₁ (bottom) for the polarizable, and the best-performing nonpolarizable (CHARMM36 and Slipids,¹¹⁹ data from ref (36)), force fields. Note that the top panel y-axis is logarithmic to visualize the slow dynamics of the Drude-based models. Experimental values are from ref (117). For the simulated τ_eff, the data point quantifies the average over the C–H bonds. If τ_eff could not be determined for all bonds due to slow convergence, then only the range from the mean of the lower to the mean of the upper error estimates is shown. For R₁, the error bars were smaller than the symbol size. All of the simulations shown here were salt-free.