The bottom panel shows the component probabilities for the A = 60.7 Å2 simulation, pm(z) along the bilayer normal z for water (w), choline (chol), phosphate (phos), glycerol (gly), and carbonyls (co) on the left, and on the right for combinations of some of these components, phosphate + choline (PC), carbonyl + glycerol (CG), and water + choline, with chain methylenes (CH2) and terminal methyls (CH3) and their sum in the middle. The Gibbs dividing surfaces are indicated by vertical dashed lines labeled DC for the hydrocarbon boundary and 0.5DB for the Luzzati water boundary. The top panel shows deviations of ptot(zi) from unity with the right half from the six-component analysis and the left half from the seven-component analysis.