  The transition interface sampling (TIS) technique allows to overcome large
free energy barriers within reasonable simulation time, which is impossible for
straightforward molecular dynamics. Still, the method does not impose an
artificial driving force, but it surmounts the timescale problem by an
importance sampling of true dynamical pathways. Recently, it was shown that the
efficiency of TIS to calculate reaction rates is less sensitive to the choice
of reaction coordinate than those of the standard free energy based techniques.
This could be an important advantage in complex systems for which a good
reaction coordinate is usually very difficult to find. We explain the
principles of this method and discuss some of the promising applications
related to zeolite formation.
