Area compressibility and buckling of amphiphilic bilayers in molecular dynamics simulations.
The elastic modulus or area compressibility of a membrane is routinely calculated in molecular dynamics simulations as the proportionality constant relating surface tension and projected surface area. Recent studies, however, have revealed a marked system size dependence of these moduli, which we attribute to the neglect of thermal undulations in the area calculation. We discuss several methods, based on the Helfrich model and on numerical triangulation, to remedy this situation, and find a satisfying agreement between them. The Helfrich model also quantitatively describes a buckling transition observed for compressed bilayers.
den Otter
W K
WK
Computational Dispersion Rheology, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede, The Netherlands. w.k.denotter@utwente.nl
D019245:Compressive Strength; D003198:Computer Simulation; D008051:Lipid Bilayers / Q000737:chemistry*; D008962:Models, Theoretical; D013501:Surface-Active Agents / Q000737:chemistry
D008051:Lipid Bilayers; D013501:Surface-Active Agents