FIG. 4.

(a) We plot the error E, as defined in Eq. (74) as a function of the splitting time step Δt_split. For the smallest time step, Δt_split = 0.001, the error remains small for case 6 but is larger for cases 1 and 4, in which some or all of the reactions are diffusion limited. (b) The average number of S₄ molecules over time in case 1. We see that the hybrid method with Δt_split = 0.1 underestimates the average number of S₄ molecules but still produces better results than with a pure mesoscopic simulation. The hybrid method matches the microscopic results closely for Δt_split ≤ 0.01.