Length scales of lipid dynamics and molecular dynamics.

Following a brief overview of length scales and system size in computer simulation, it is demonstrated that a simulation sized lipid bilayer (typically a 50 x 50 A2 patch) is in the regime where stretching dominates undulation, while the reverse holds for a flaccid macroscopic membrane. Then it is estimated that current system sizes of membrane simulations must be increased by at least a factor of 10 before thermodynamic limits are approached for quantities such as surface tension.