[Pw_forum] Get wrong symmtry

[yumin qian]

   Thanks for your reply ,
 But what is the problem is ?
 I think there is nothing wrong to do with numerical accuracy , there may be
something wrong with the code itself , could anybody give me a suggestion
 to the solution of this problem?

2008/11/10 Michael Mehl <rcjhawk at gmail.com>

> Axel Kohlmeyer wrote:
> > On Sun, 9 Nov 2008, yumin qian wrote:
>
> > how about not having enough numerical accuracy
> > for the numbers in the z-coordinate?
> >
> > axel.
>
> That would appear not to be the case.  The requirement for P4/nmm
> symmetry is that z for the second atom in a pair be equal to -z (or 1-z)
> for the first atom.  That's the case here.  Whatever the problem is,
> it's not in the coordinates.
>
> (See http://cst-www.nrl.navy.mil/lattice/struk/AsCuSiZr.html)
>
> >
>
> > YQ> ATOMIC_POSITIONS
> > YQ> La    0.2500000000    0.2500000000    0.1461000000
> > YQ> La    0.7500000000    0.7500000000    0.8539000000
> > YQ> O     0.7500000000    0.2500000000    0.0000000000
> > YQ> O     0.2500000000    0.7500000000    0.0000000000
> > YQ> Fe    0.7500000000    0.2500000000    0.5000000000
> > YQ> Fe    0.2500000000    0.7500000000    0.5000000000
> > YQ> As    0.2500000000    0.2500000000    0.6369000000
> > YQ> As    0.7500000000    0.7500000000    0.3631000000
>
> --
> Michael Mehl, Naval Research Laboratory, Washington DC.
> Sabbatical Duke University through July 2009.
>
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-- 
Sincerely Y. M. Qian
Lab.of Condensed Matter Theory and Materials Computation
Institute of Physics
Chinese Academy of Sciences
Tel:  + 8610 8264 9147
E-Mail:yuminqian at gmail.com <E-Mail%3Ayuminqian at gmail.com>
P.O.Box 603   Beijing 100190
China
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