Distribution of neighboring lipid molecules around a DMPC molecule. (a) Schematic diagram of molecular locations under a hexagonal arrangement structure. Red balls represent the locations of molecules; V_ij is the vector from molecule i to j. (b) Radial distribution density of neighboring molecules around a DMPC molecule, black and red lines show the cases at 330 K and 300 K, respectively. (c) Probability distribution (p) of neighboring molecules around a DMPC molecule with respect to the angle θ between V_ij and the x-axis of the simulation box. The upper and lower panels represent the cases where V_ij points from a DMPC molecule to the nearest neighbor and the second-nearest neighbor, respectively. Gray circles and red squares correspond to the conditions with system temperatures at 330 K and 300 K, respectively.