Figure 6.

The transition probability P calculated at 300 K vs. time along the 400-K trajectory shown in Figs. 1 and 2 for the (Left) F ⇌ H and (Right) S ⇌ U transitions for conformations in the transition region. The solid line is the order parameter used to discriminate states, i.e., (Left) hydrogen bonds N_HB and (Right) core size R_core. The dashed line is a fit to P = (erf[(t-t_TS)/t_trans]+1)/2, where t is time, t₀ is the time at which P = 1/2 (that is, near the TS) and t_trans is the duration of the transition region. We see that P_F⇌H(C) and P_S⇌U(C) change sharply from 0 to 1 over a few ps time interval (with t_trans = 7.0 and 1.3 ps, respectively, at 400 K). Transition probabilities for this 400-K run calculated at 400 K are indistinguishable within error from the 300-K probabilities presented here.