FIGURE 1.

Illustration of the simulated system used to determine the dielectric constant. The system contains 128 POPC lipids, 4204 SPC waters, and two uncharged LJ cavities. One cavity is harmonically restrained in its z motion relative to the bilayer about a position z₀. The other cavity is harmonically restrained in its z motion relative to the bilayer about a point at z₀ − 30 Å. This allows both bilayer leaflets to be studied simultaneously from a single simulation. A separate simulation was carried out for each value of z₀ from 0 to 30 Å in 2 Å increments. The system is periodic in three dimensions.