Table 1. Definitions of variables used in equations (1–6).

Variable	Definition
σo	Intrinsic charge density of the outer bilayer
σi	Intrinsic charge density of the inner bilayer
Φi	Potential at the inner bilayer surface
Φo	Potential at the outer bilayer surface
Vm	Potential between inner and outer bulk solutions (outer at zero)
ΔΦso	Potential drop at outer bilayer due to Stern layer
ΔΦsi	Potential drop at inner bilayer due to Stern layer
εb	Permittivity of lipid bilayer
δb	Width of lipid bilayer
εTsol	Permittivity of bulk aqueous solution at temperature T
cjo(∞)	Concentration of jth ionic species in outer buffer
cki(−∞)	Concentration of kth ionic species in inner buffer
zjo	Valence of jth ionic species in outer buffer
zki	Valence of kth ionic species in inner buffer
δso	Thickness of Stern layer at the outer bilayer
δsi	Thickness of Stern layer at the inner bilayer
εso	Dielectric constant of outer Stern layer
εsi	Dielectric constant of inner Stern layer
rjo	Hydrated ionic radius of jth ionic species in outer buffer
rki	Hydrated ionic radius of kth ionic species in inner buffer
δlipido	Hydrated size of the outer polar lipid head groups
δlipidi	Hydrated size of the inner polar lipid head groups