To conclude, we have provided a molecular-level view into the structures of the L o phase across a range of temperatures in binary DPPC/CHOL mixtures and in ternary DPPC/DOPC/CHOL mixtures. Both mixtures are expected to be in the L o phase across the studied temperature range from 293 K to 333 K. Still, we discovered two different regimes separated by a crossover at either T ter co ≈308 K or T bin co ≈318 K, yet no lipid demixing was observed.