In the spherical case, d FG refers to the diameter of the FG region, and d CG represents twice the distance between the start of the CG region and the closest box wall (or, equivalently, the minimum width of the CG region via periodicity), so that, here as well, L = d FG + 2d SG + d CG . The equations below assume that the representative periodic copies of the solvent molecules are selected at minimum-image positions relative to the center of the computational box. ) and ( ).