[gmx-users] pressure coupling for lipid bilayer

[David L. Bostick]

I use anisotropic with

compressibility         = 4.5e-5 4.5e-5 4.5e-5 0.0 0.0 0.0

It seems to work quite well.  Since the 0.0 compressibilities of the
off-diagonal elements keep the box from deforming.

David

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David Bostick					Office: 262 Venable Hall
Dept. of Physics and Astronomy			Phone:  (919)962-0165 
Program in Molecular and Cellular Biophysics 
UNC-Chapel Hill					
CB #3255 Phillips Hall				dbostick at physics.unc.edu	
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On Wed, 1 May 2002, Shang-Te Danny Hsu wrote:

> Hi!
> 
> There has been some discussions about proper pressure coupling for lipid 
> bilayer. My experience is that the anisotropic or semiisotropic coupling 
> with compressibility of 6e-5 or 4.5e-5 along the membrane normal easily 
> deforms the bilayer in < 20ps and eventually the bilayer is flattened!! 
> On the other hand, with isotropic or without any P-coupling, the system 
> is running quite well.
> 
> Surface tension coupling method is suggested to be a nice approach (J. 
> Chem. Phys. 111(3):1281), but the parameters are not trivial. Without 
> experimental data on hand, it is difficult to estimate surface tension 
> (in my case, POPC bilayer). In addition, the incorporation of other 
> molecules may alter the surface tension again!
> 
> How should I setup up such a system properly???
> -- 
> Shang-Te Danny HSU
> Department of NMR Spectroscopy
> Bijvoet Center for Biomolecular Research
> Utrecht University
> Padualaan 8, 3584 CH Utrecht, the Netherlands
> phone: +31-30-2539931 | fax: +31-30-2537623
> e-mail: hsu at nmr.chem.uu.nl
> 
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