Membranes function as biological barriers that separate cells from the environment and delineate different cellular compartments; they are crucial in maintaining the life sustaining chemical and electrical gradients. The key structural constituents of membranes are phospholipids that form the membrane surface with their polar head groups and the membrane core with their lipophilic tails (Fig ). In addition to phospholipids, biological membranes contain for example cholesterol, proteins, ions, and oligosaccharides. Lipid bilayers play central role in several biological and pathological processes such as cell division, intracellular membrane trafficking, and formation of lipid rafts . To fully understand these processes, atomistic and molecular level understanding of lipids is required . Such understanding can be obtained through computational tools, but it is important that tools used depict the structure, dynamics, and function of lipid bilayers accurately.