FIG. 6.

We demonstrate the dependence of system size, N, on the mole fraction, $x_{\text{D}}$. (a) Free energies of mixed (dotted), stripe (solid), and dot (dashed) phases when $\chi$ = 2.90 cal/mol and T = 295 K. z = 6 to approximate realistic packing of lipids. (b) Solid line is the relation from the binary Flory-Huggins model [Eq. (S6) of the supplementary material] with x_D = 0.45, T = 295 K, and z = 6. Circles are placed on the curve at critical sizes (N_c) obtained from simulation, while squares are placed on the curve at $\chi$ values derived by Almeida.⁹⁵ $\chi$ and N_c values are tabulated along with corresponding line tensions in Table S3 of the supplementary material.