Autocorrelation function of the principal mode motion.

The autocorrelation function C(t) of the internal dynamics along the first principal component (Eq. S5; blue line) is fitted with a two-exponential function (Eq. S6; red line). The parameters extracted by curve fitting are: a = 0.49; τ_fast = 0.4 ns; τ_slow = 12.9 ns.