Place: DPG Spring Meeting 2009, Dresden, Germany
The dynamical properties of complex systems are often characterized by the existence of several (meta)stable states separated by large free energy barriers. Examples for such complex systems are omnipresent throughout nature varying from conformational changes in biological relevant molecules to phase transitions as well as many chemical reactions. The long time dynamical behavior of these systems is usually determined by transitions between the stable states. However, the sampling of such transition networks is often severely hampered by the high free energy barriers between the states making it unfeasible to use regular molecular dynamics simulations.Transition path sampling (TPS) has been successfully applied to study such rare events, but is limited to processes between two distinct stable states. Here, we extend TPS to include multiple stable states. Combining this approach with transition interface sampling and replica exchange ideas, we not only improve sampling efficiency, but also access kinetics, mechanisms and free energies of all possible transitions within the system in one single simulation.