From: Salvatore Mario Cosseddu (S.M.Cosseddu_at_warwick.ac.uk)
Date: Tue May 17 2011 - 15:06:51 CDT

I think this is the wrong mailing list... it's a charmm force field
problem (namd-l would be better)

by the way. try

useConstantArea yes

after a proper relaxation time in the npt (up to you)

otherwise you are supposed to put a non zero surface tension.

Look around to membrane simulation papers, because it's a well known
issue of CHARMM force field.

On 17/05/11 17:34, kanchi subbarao rao wrote:
> hi all
> i am new namd user. i am running simulation of dppc-bilayer
> by using charm-27 force field. i am facing a problem how to maintain
> constant area per lipid while running simulation in NPT and NVT
> ensembles.