has characteristic Smoluchowski equation based method Greens function reaction dynamics http://identifiers.org/doi/10.1063/1.2137716 GFRD Green's function reaction dynamics Method that simulates biochemical networks on particle level. It considers both changes in time and space by ''exploiting both the exact solution of the Smoluchowski Equation to set up an event-driven algorithm'' which allows for large jumps in time when the considered particles are far away from each other [in space] and thus cannot react. GFRD combines the propagation of particles in space with the reactions taking place between them in one simulation step. spatial description discrete variable progression with adaptive time step approximate solution