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

[Gabriele Sclauzero]

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