[gmx-users] Re: Warning: pressure scaling more than 1%

Wissensbund at gmx.net Wissensbund at gmx.net
Tue Feb 5 15:51:10 CET 2008

Dear gmx-users.

It is a pity no one wanted to help me,
but I have found the answer by myself
and want to share it with you...

For the problem with the pressure scaling
more than 1% I can recommend to use the
following link:


After increasing the tau_p up to 1.0 ps
the Simulation worked very well...


Wissensbund at gmx.net wrote:
> Dear gmx-user.
> I try to start simulating bilayer membrane systems for which I need to 
> set the pressure coupling semiisotropic...
> After processing mdrun I get quite a lot of WARNINGs telling:
> Warning: pressure scaling more than 1%
> Does this mean that I did not run the energy minimization long enough 
> and there are some high forces?  Is there something else that I am 
> doing wrong?
> In my mdp file, the pressure coupling looks like:
> ; Pressure coupling
> Pcoupl                   = berendsen
> Pcoupltype               = semiisotropic
> ; Time constant (ps), compressibility (1/bar) and reference P (bar)
> tau_p                    = 0.2  0.2
> compressibility          = 4.5e-5  4.5e-5
> ref_p                    = 1.0  1.0
> Thanx,
> Mark

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