  We present an efficient method to compute transition rates between states for
a two-state system. The method utilizes the equivalence between steady-state
flux and mean first passage rate for such systems. More specifically, the
procedure divides the configurational space into smaller regions and
equilibrates trajectories within each region efficiently. The equilibrated
conditional probabilities between each pair of regions lead to transition rates
between the two states. We apply the procedure to a non-trivial coarse-grained
model of a 70 residue section of the calcium binding protein, calmodulin. The
procedure yields a significant increase in efficiency compared to brute-force
simulations, and this efficiency increases dramatically with a decrease in
temperature.
