[Pw_forum] the high symmetry line of bcc phonon dispersion calculated by pw4.1.2

[Wei Zhou]

o ,I see ,pherhaps the choice of the crystal axis in PW  is different ,so
the coordination is different, what I worry is that how I can know the
correct coordinations for the next structure in the further unknown work.
is there is a correctle and sately way ?

finally thank you for all your relpies


>
> Wei Zhou wrote:
> > in fact, I just get the coordination from the web
> > :http://www.cryst.ehu.es/cgi-bin/cryst/programs/nph-kv-list
> > k-vector label Wyckoff position  Parameters
> > CDML  ITA  ITA
> > GM  0,0,0  4  a  m -3 m  0,0,0
> > H  1/2,-1/2,1/2  4  b  m -3 m  0,1/2,0
> > P  1/4,1/4,1/4  8  c  -4 3m  1/4,1/4,1/4
> > N  0,0,1/2  24  d  m.mm <http://m.mm>  1/4,1/4,0
> > and I turn them into Cartesian coordinates and units of 2\pi/a, then I
>
> I'm sure that the points you gave in the previous email (those leading to
> the "wrong"
> dispersion) are not correct in cartesian _coordinates_, maybe because the
> choice of the
> crystal axis in PW and in the database do not coincide, so that you cannot
> simply multiply
> the crystal coordinates by the PW basis vectors written in cartesian
> coordinates.
>
> Anyway, in the last column here above I see that you have already the
> correct cartesian
> points in \pi/a units, so why bother?
>
>
> GS
>
> > plot the phonon dispersion curve , the results is wrong ,it seems the
> > coordination dos not correct,then I feel puzzled.
> >
> >
> >      > then I feel puzzled, would some one give some idea about this?
> >      > any help will be appreciated
> >      >
> >      > --
> >      > ZhouDawei
> >      > JiLin Universiyt ,ChangChun ,China
> >      > zdw2000 at gmail.com <mailto:zdw2000 at gmail.com>
> >     <mailto:zdw2000 at gmail.com <mailto:zdw2000 at gmail.com>>
> >
> >     --
> >
> >
> >     o ------------------------------------------------ o
> >     | Gabriele Sclauzero, PhD Student                  |
> >     | c/o:   SISSA & CNR-INFM Democritos,              |
> >     |        via Beirut 2-4, 34014 Trieste (Italy)     |
> >     | email: sclauzer at sissa.it <mailto:sclauzer at sissa.it>
> >               |
> >     | phone: +39 040 3787 511                          |
> >     | skype: gurlonotturno                             |
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> >
> >
> >
> > --
> > ZhouDawei
> > JiLin Universiyt ,ChangChun ,China
> > zdw2000 at gmail.com <mailto:zdw2000 at gmail.com>
> >
> >
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>
> o ------------------------------------------------ o
> | Gabriele Sclauzero, PhD Student                  |
> | c/o:   SISSA & CNR-INFM Democritos,              |
> |        via Beirut 2-4, 34014 Trieste (Italy)     |
> | email: sclauzer at sissa.it                         |
> | phone: +39 040 3787 511                          |
> | skype: gurlonotturno                             |
> o ------------------------------------------------ o
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-- 
ZhouDawei
JiLin Universiyt ,ChangChun ,China
zdw2000 at gmail.com
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