The pressure-area isotherms. The pressure-area isotherms obtained from the DPD simulations at different temperatures are depicted in Figure , along with several experimental measurements, including our data and data from the literature. The experimental data produced by several groups show substantial deviations, as discussed in the introduction. When compared with simulation results, one needs to consider the differences in time and length scales. Our largest monolayer in the simulations is about 56 nm, which is still much smaller than the micrometer-sized kidney-shaped monolayer domains observed through imaging techniques (Figure ). Such large-scale structures may affect surface pressures at high areas per lipid, causing substantial non-uniformity that cannot be captured by a 50 nm film in simulations. As the area per lipid increases, the monolayer becomes more uniform, allowing it to be represented by small patches of films with periodic boundary conditions. On the other hand, at high compressions, the monolayers in experiments tend to collapse, reducing the surface pressure. However, in simulations, the periodic boundary conditions can prevent local deformations and lead to metastable states of high compression.