Transition path sampling: throwing ropes over mountains in the dark

Understanding rare transitions occurring in complex systems, for instance c hemical reactions in solution, poses the problem of finding and analysing t he trajectories that move from one basin of attraction to another on a comp licated potential energy surface. We have developed a systematic approach f or Ending these trajectories using computer simulations without preconceive d knowledge of transition states. The approach follows from a novel statist ical mechanics and thermodynamics of trajectories and has been demonstrated with several applications.