The Smoluchowski approach requires the diffusion process to be followed using very short timesteps as the distance between the two entities must be precisely monitored over time. However, since the detailed diffusion process is of little interest in biological terms, this requirement translates into an unnecessary computational overhead, as illustrated in Figure 1. In order to circumvent this problem, Andrews and Bray recently devised a scheme which corrects σb for longer timesteps, making it more useful for simulating biological systems [17].