[Pw_forum] orthogonality of phonon eigenvectors?

[Suza W]

 Dear All ,


> > IIRC the phonon code, and all other auxiliary codes, always print
> > displacement patterns, not phonon eigenvectors
>
>   Not always, perhaps. In case of a homo-atomic system, the phonon
eigen-vectots (v)
  can directly be  presented as atomic displacements (u) . However, for a
hetero-
  atomic system, it is not so straight-forward. We need  some more algebra,
because

 u = v / sqrt (M)   and  SUM_i  ( u_i . u_i . M_i )  = constant  .

 After that one can obtain correct atomic displacement  from the
eigen-vectors in case of a
 hetero-atomic system.

 Now I am going to ask here a different question.
 In the PWFORUM, I have found some discussions about Dario Alfe's PHON
code.
 Is here anybody who has used this code to obtain the full phonon
dispersion for BaTiO3 ?
 In the example directory of the PHON code, I find  Al, and MgO  as the
test cases.
 Please do share the files for BaTiO3 as well, if available.

 Thanking you all,

 Yours sincerely,
 Suza
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