[gmx-users] Pressure coupling constants

[Michael Shirts]

If the goal is to get the system to relax from a compressed state as
part of preparation, then berendsen pressure coupling is the best way.
 However, it is not a physical method -- it overly constraints the
volume distribution (which is one of the reasons it's good to force a
system into a reasonable state).

shorter tau_p and also short tau_t will help the relaxation occur
without the simulation blowing up.

If you want to get any meaningful physics at equilibration, then use
MTTK or Parrinello-Rahman.

None of the barostats are physically meaningful for nonequilibrium
expansion or compression.



On Thu, Dec 12, 2013 at 12:11 PM, kpsanto <santo.kp at gmail.com> wrote:
> Hi all
> I am using NPT ensemble to relax a highly compressed system.  I find that
> the way it relaxes depends on the pressure coupling constant ( berendsen
> barostat). My question is if the choice of the coupling constant would
> depend on the system conditions? The compressed system would tend to at
> expand faster rate and accordingly one should use a coupling constant much
> smaller than usual?
>
> Thanks
> Santo
>
> -----
> K. P. Santo
> Post doctoral fellow
> Department of Chemistry
> University of North Carolina at Chapel Hill
> Chapel Hill, NC, USA
>
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