thanks for your  reply

i have some relevant publications  people work on such systems using
gromacs..(classical method)
should i use that one?



On Wed, Dec 21, 2011 at 8:59 PM, <[email protected]> wrote:

> In principle, yes... But take care:
> if you work over a large interval of pressures
> with a fixed-basis code like Siesta, the quality of basis
> is not equally good everywhere,
> so that you might be pretty off either on the low-pressure end
> or on the high-pressure end, depending on how/where you basis
> has been optimized.
> A test on a smaller representative system
> against a planewave code might be useful,
> to estimate the error...
>
> Best regards
>
> Andrei Postnikov
>
>
> > Of course. Assuming your start denisity is not to faw away from a real
> > system, you can use variable cell optimization, and increase the target
> > pressure. If you have 2 values for the pressure, you could could estimate
> > by linear extrapolation the final pressure which corresponds to the
> target
> > density.
> >
> > Best regards
> > Michael
> >> hello!!
> >>
> >> i have a long polymer chain of about 420 atoms ..
> >> can i compress it to target density of 1.35gm/cm3  using SIESTA??
> >> As i have seen in a paper in which people take a long chain of polymer
> >> and
> >> wrap around cluster and then compress the system to target(bulk density)
> >> using  GROMACS.
> >>
> >> Can it be possible with SIESTA? if yes then please tell me how?
> >>
> >> thanks ..
> >>
> >
> >
> > --
> > Michael Schuch
> > FB. Physik / AG. Statistische Physik
> > Barbarastrasse 7
> > 49069 Osnabrück
> >
> >
>
>

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