[Pw_forum] help

[Axel Kohlmeyer]

On 9/10/06, Amin Babazadeh <babazade at gmail.com> wrote:
>
> Dear Dr.Paolo

dear amin,

> I want to simulate a nanostructure with using espresso code.For doing it i
> made a zns supercell, and after that i omitted some of the atoms .After
> omitting i think the crystal looks a nanostructure.

it is some kind of a nanostructure, in the sense that it is a cluster.
however, you seem to be not paying enough attention to both the
chemistry (with a Zn:S ratio of 6:4 your cluster is either charged or
you'll have to have_very_ unusual bonding) and the physics (with a
cell size of > 30 a.u. the irreducible brillouine zone is small and
thus the need for extensive k-point sampling not very high, especially
with a compound like ZnS).

>  Do you think I could simulate nanostructure with using this method.
> I should say that the pw.x command run without any error for this structure.
> I will appreciate if you say your idea about my job.

the main suggestion would be that you first get more knowledgable
about the theory behind plane-wave pseudopotential calculations
in periodic systems. there are a number of fine text books available
(just search through the mailing list archives for some recommendations).
on that topic.

cheers,
    axel.
>
>
>
> On 9/8/06, Paolo Giannozzi <giannozz at nest.sns.it > wrote:
> > On Friday 08 September 2006 09:38, Amin Babazadeh wrote:
> >
> > > I want to simulate a nanostructure with using espresso code so I give
> > > this structure [...]
> > > The calculation for pw.x was good but my problem is in finding band
> > > structures. I don't know what k-points is good for this structure.
> >
> > are you sure k-points are "good" ( i.e. a useful concept) for this
> > structure? It looks like you are studying a small ZnS clusters using
> > a fcc supercell.
> >
> > Paolo
> > --
> > Paolo Giannozzi             Phone:   +39/050-509876
> > DEMOCRITOS and SNS          Fax:     +39/050-563513
> > Piazza dei Cavalieri 7      I-56126 Pisa, Italy
> > _______________________________________________
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> > Pw_forum at pwscf.org
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> >
>
>
>
> --
> AMIN


-- 
=======================================================================
Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
  Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
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