Different direct integrators for Redfield equations applied to electron transfer dynamics

The numerical efficiency of different schemes for solving the Liouville-von Neumann equation within Redfield theory has been studied. Among the tested algorithms are the general Runge-Kutta and Bulirsch-Stoer methods as well as methods especially developed for time propagation like the Short Iterati ve Arnoldi and Newtonian propagators. Also two different time step control mechanisms have been applied. The calculations have been performed for a sy stem consisting of two charge localization centers modeling electron transf er. Two different cases have been investigated, i.e., the coherent dissipat ionless and the dissipative case. The tested integrators perform quite diff erently for these cases. (C) 2000 Elsevier Science B.V. All rights reserved .