Figure 4

(Color online) Toy model of ion channel. (a) Reaction potential for a cation that moves along different trajectories parallel to the channel axis. A sketch of the channel profile is represented as a gray region. (b) Gauss's law check. The total charge induced on the dielectric boundary is plotted as a function of the position of the ion along the trajectories. The numerical error introduced by the computation is limited to 3% of an elementary charge.