[QE-users] question about wave functions phonon code

[Paolo Giannozzi]

On Sat, Sep 25, 2021 at 2:00 AM Jacopo Simoni via users <
users at lists.quantum-espresso.org> wrote:

This wave function appears different from the wave function at an
> equivalent q point, for instance if I look at evq at q=(0,0,1), this is
> different from evq at (1,1,0) that are equivalent by translation of a G
> vector (I am thinking here at a FCC periodic lattice). The two functions
> just differ by a phase factor or I am missing something ?
>

They differ by a phase factor; moreover, in the presence of degenerate
eigenvalues, you have no guarantee that the eigenvectors in the degenerate
subspace are the same. Finally, the ordering of k+G components is not
necessarily the same in the two cases

Paolo

Thanks in advance,
> Jacopo Simoni, Lawrence Berkeley National Lab.
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-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 206, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
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