All free energy surfaces (top-down view) for nine neutral pore-binding inhibitors, in blue, produced from metadynamics simulations with positions of top five clusters, plus an additional four versions of protonated versions of four of these, in red (flecainide, mexiletine, bupivacaine, and etidocaine). Red circles on the chemical structures highlight the positions of the protonations and green circles highlight the positions of chiral centers. Darkest color represents 0 kJ/mol or the most favorable drug binding sites; contours are plotted every 4 kJ/mol, where lighter colors indicate higher energy or less favorable regions of the pore.