[gmx-users] Which MD ensemble?

[Anton Feenstra]

Nuno R. L. Ferreira wrote:
> Hello
> 
> A question that is always puzzling me.
> Is there any rule when choosing an ensemble for the production run?
> 
> I understand that during a solvent equilibration run, we better start with
> an NVT and then do a NPT.
> What about after having the system box ready for a long run?

Generally speaking, one would like to duplicate 'laboratory' conditions,
which mostly are NPT. NVT would be fine, too, as long as your average
pressure and/or density are what they should be. The only real difference
for long, eventful simulations would be when a phase transition occurs
(e.g. proten un-/folding, membrane phase change) which would cost/gain
energy and may change equilibrium densities and hence may lead to
temperature and/or pressure changes.


-- 
Groetjes,

Anton
  _____________ _______________________________________________________
|             |                                                       |
|  _   _  ___,| K. Anton Feenstra                                     |
| / \ / \'| | | Dept. of Pharmacochem. - Vrije Universiteit Amsterdam |
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