Figure 1.

Projection error (ϵ) for varying number of molecules given τ_D=0.1 s, ℓ=0.62 μm, and D=0.001 μm² s⁻¹. Adaptive step splitting allows us to take advantage of the independence of diffusing molecules and the nonlinear relationship of projection error to the number of molecules diffused to reduce the total error of diffusion step over τ_D by splitting it into sub-subproblems of fewer molecules rather than by splitting the time step.