To evaluate the differences in ion solvation between acyclic transporter 1 and cyclic transporter 2, we performed equilibrium (3 x 100 ns) MD simulations of the transporters in complex with Cl - and OH -at the membrane interface. Harmonic restraints (2000 kJ mol⁻¹ nm⁻²) were applied between the iodines and the anion's heavy atom at the DFT-optimised distance. Membrane simulations followed established protocols (see §8 SI for details), using POPC bilayers with the Stockholm lipid parameters in the TIP3P-FB model for water. The oxygen-ion radial distribution functions (RDFs, Figure and S56-S57) represent the timeaveraged distance distribution between the oxygen of water and the Cl -or OH⁻ oxygen atom.