Asymmetric Bilayer Phase Diagram

Interactive phase diagram calculator for asymmetric lipid bilayers based on the Bragg–Williams mean-field model: f(φ,ψ) = f_BW(φ) + f_BW(ψ) + Λ(φ−ψ)². Here φ and ψ are the ordered-lipid mole fractions in the upper and lower leaflets, χ is the Flory–Huggins interaction parameter, and Λ is the interleaflet coupling. Three morphology types arise depending on Λ relative to Λ_C = χ−2 and Λ* = 1.5χ(χ−2)/(2χ−3): Type 1 (Λ ≤ Λ_C, T-junction), Type 2 (Λ_C < Λ < Λ*, interior lenses), and Type 3 (Λ ≥ Λ*, R_D+R_O only). Phase notation follows Kennison et al. (2024).