Optimizing replica exchange moves for molecular dynamics

We sketch the statistical physics framework of the replica exchange technique when applied to molecular dynamics simulations. In particular, we draw attention to generalized move sets that allow a variety of optimizations as well as new applications of the method.

Figure 1

Sketch of the basic situation in replica exchange simulations: simulations run independently on stochastic samplers with weight function $w_i\left(S\right)$; at certain times, exchange of the current conformations is attempted with probability $p_M$, Eq. (3).

Figure 2

Sketch of the coordinate part of the phase space for constant-energy replica exchange simulations. Exchange moves are possible in the overlap region.

Figure 3

Dependence of the average acceptance probability $⟨p_M⟩$ on the distance of the energy shells [see Eq. (23)] in microcanonical replica exchange simulations.