Ion trajectories for simulations with pure CsCl. (A–F) For simulations with CsCl (900 mM) with Cs⁺ preplaced in p23 and p34 from simulations conducted at −700 mV (A), −500 mV (B and C), and −250 mV (D and E). A simulation conducted at −150 mV and a cation concentration of 500 mM is depicted in F.