  Computer simulations of coarse-grained molecular models for amphiphilic
systems can provide insight into the the structure of amphiphiles at
interfaces. They can help to identify the factors that determine the phase
behavior, and they can bridge between atomic descriptions and phenomenological
field theories.
  Here we focus on model systems for amphiphilic membranes. After a brief
general introduction, we present selected simulation results on monolayers,
bilayers, and bilayer stacks. First, we discuss internal phase transitions in
membranes and show that idealized models reproduce the generic phase behavior.
Then we consider membrane fluctuations and membrane defects. The simulation
data is compared with mesoscopic theories, and effective phenomenological
parameters can be extracted.
