Transition events in butane simulations: Similarities across models

From a variety of long simulations of all-atom butane using both stochastic and fully solved molecular dynamics, we have uncovered striking generic behavior that also occurs in one-dimensional systems. We find an apparently universal distribution of transition event durations, as well as a characteristic speed profile along the reaction coordinate. An approximate analytic distribution of event durations, derived from a one-dimensional model, correctly predicts the asymptotic behavior of the universal distribution for both short and long durations.