[gmx-users] pressure coupling for lipid bilayer

[Anton Feenstra]

Shang-Te Danny Hsu wrote:
> 
> It might be a trivial question, but how do you determine the surface area per lipid?
> 
> What I used is by "g_sas" (solvent accessible surface) to calculate all solute (72 POPC) SAS.
> 
> The mean total area is about 1450 A**2 with hydophilic area of 550 A**2
> (supposed to be the head group). Then I will obtain only 2*SAS/(# of
> lipid) = 42 A**2, which is way too small! However, I have the same value
> from the pre-equilibrated POPC bilayer (64 monomers) given by Marrink.
> Did I do something wrong??

It might be a trivial (and useless) answer, but wouldn't you simply 
take the surface of the two lateral box plane (e.g. the x- and y- box 
lengths multiplied) and devide that by the number of monomers?

-- 
Groetjes,

Anton
 ________ ___________________________________________________________
|        | Anton Feenstra                                            |
| .      | Dept. of Pharmacochemistry - Free University Amsterdam    |
| |----  | De Boelelaan 1083 - 1081 HV Amsterdam - The Netherlands   |
| |----  | Tel: +31 20 44 47608 - Fax: +31 20 44 47610               |
| ' __   | Feenstra at chem.vu.nl - http://www.chem.vu.nl/afdelingen/FAR|
|  /  \  |-----------------------------------------------------------|
| (    ) | Dept. of Biophysical Chemistry - University of Groningen  |
|  \__/  | Nijenborgh 4 - 9747 AG Groningen - The Netherlands        |
|   __   | Tel +31 50 363 4327 - Fax +31 50 363 4800                 |
|  /  \  | K.A.Feenstra at chem.rug.nl - http://md.chem.rug.nl/~anton   |
| (    ) |-----------------------------------------------------------|
|  \__/  | "This Doesn't Suck, It's a Black Hole !" (K.A. Feenstra)  |
|________|___________________________________________________________|