System geometry corresponding to electrostatic and elasticity calculations. (A) Cross section of the deformed membrane showing the flat lower leaflet and curved upper leaflet (solid red). L₀ is the equilibrium membrane width and h is the height of the upper leaflet. The midplane is assigned z = 0 (dashed black). The radius of the TM helix is r₀ and only half of the helix is pictured. (B) The idealized helix is shown and the contact curves of the upper and lower membrane leaflets are shown in red. The lower curve is flat; however, the upper curve dips down with a minimum value at the position where the central residue resides on the full molecular helix when present.