[gmx-users] Parrinello-Rahman with surface-tension coupling

[Felipe Pineda, PhD]

Thanks for the advice, Mark!

I did exactly this experiment with the same expectations before posting 
my query. I didn't get any complaint neither from grompp nor from mdrun, 
what doesn't necessarily mean that this combination is implemented. I 
just noticed that during equilibration results deteriorate, i.e., the 
normal pressure which already was close to the target value gets 
negative, and the surface tension increases significantly over the 
target value. This could of course be an effect of the different 
pressure coupling method used.

Kind regards,

Felipe

On 08/14/2012 07:28 AM, Mark Abraham wrote:
> On 13/08/2012 7:21 PM, Felipe Pineda, PhD wrote:
>> Dear All,
>>
>> the Gromacs User Manual V.4.5.4 states on p. 33: "(...) the surface
>> tension and the z-component of the pressure can be coupled to a
>> pressure bath. Presently, this only works with the Berendsen pressure
>> coupling algorithm in GROMACS."
>>
>> My question: does this hold for V. 4.5.5 as well? Is it possible to
>> use the combination:
>>
>> pcoupl            = Parrinello-Rahman
>> pcoupltype     = surface-tension
>>
>> in an mdp file for a NPgammaT MD run?
> Probably, but you should try it and see :-) Likely grompp will complain
> if it is not implemented.
>
> Mark