As a reduced particle approach, BioMOCA replaces the explicit water molecules with continuum background and handles the ion-water interactions using BTMC method, in which, appropriate scattering rates should be chosen. In other words, ion trajectories are randomly interrupted by scattering events that account for the ions’ diffusive motion in water. In between these scattering events, ions follow the Newtonian forces. The free flight times, T f, are generated statistically from the total scattering rate according to