[Pw_forum] orthogonality of phonon eigenvectors?

[Sonu Kumar]

Dear Suza,

On Sun, Feb 12, 2012 at 5:05 PM, Suza W <suza.rri at gmail.com> wrote:

>
>
>> > if you have degenerate eigenvalues, any linear combination of
>> eigenvectors
>> > in the degenerate subspace is a solution. What you get from numerical
>> > diagonalization depends upon the phase of the moon.
>>
>>    Yes Prof. Giannozzi, in principle, it is true.
>    Nevertheless, in practice, phonon code in ABINIT
>    always renders these well-arranged eigen displacements
>    without  depending much on the phase of the moon.
>
>
>  ( 0.0   0.0    2.30182985E-05 )
>  ( 0.0   0.0    1.65666412E-03 )
>  ( 0.0   0.0   -1.75258026E-04 )
>  ( 0.0   0.0   -3.12875743E-03 )
>  ( 0.0   0.0   -1.75258026E-04 )
>
>  ( 0.0    2.30182985E-05   0.0 )
>  ( 0.0    1.65666412E-03   0.0 )
>  ( 0.0   -1.75258026E-04   0.0 )
>  ( 0.0   -3.12875743E-03   0.0 )
>  ( 0.0   -1.75258026E-04   0.0 )
>
>  (  2.30182985E-05   0.0   0.0 )
>  (  1.65666412E-03   0.0   0.0 )
>  ( -1.75258026E-04   0.0   0.0 )
>  ( -3.12875743E-03   0.0   0.0 )
>  ( -1.75258026E-04   0.0   0.0 )
>
>
I think, after applying ASR i.e. using dynmat.x, you can
obtain these well arranged eigen vectors. Although no so sure.

regards,
Sonu
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