[gmx-users] Surface tension help!

[Hector Mtz-Seara]

Dear all,

I've been some time working on monolayers and bilayers and as normal I 
have not enough experience in many of the issues involving it.  I want 
to ask about the values of the surface tension that GROMACS give us. Are 
they accurate enough?, because I'm experiencing problems trying to 
reproduce a monolayer isotherm of carboxylic acid and DPPC (Tieleman) 
(GROMACS FORCE FIELD). Also I will like to know if surface tension bath 
works properly expecting from it a good concordance with experimental 
result, as the oscillation of the surface tension values fluctuate so 
much I mean in the same order value of the reference value. Also trying 
the NVT ensemble I always get values that give me negative surface 
pressure when I'm staying in surface areas that are suppose to be allowed.

Well summarizing It's possible to construct a Isotherm?, and if you 
think yes ( a real one, not two points, without a reparametritzation) 
tell me which ensemble is better and any detail you can.

Any idea will be grateful, any paper that calculates  isotherms with 
GROMACS  with detailed procedure will be also great.

Thank you in advance.

Hector

University of Barcelona