[Pw_forum] Phonon DOS per polarization

[Lorenzo Paulatto]

On 26 October 2012 07:55, Bo Qiu <200210qb at gmail.com> wrote:

> Dear Dr. Paulatto,
>
> Thanks a lot for the explanations! I'm actually writing a small code to
> order phonon bands based on eigenvector continuities on a 3d grid. Thanks
> for pointing out there is already such option in matdyn.x, I'll definitely
> check it out. I have finished a preliminary test for my code on Al for a
> band crossing along Gamma-K direction -- it seems to be well captured,
> but band orderings are wrong at some random point where there is actually
> no band crossing. I'll try to figure it out and also referring to the
> matdyn.f90 to see what else I can do.
> On the other hand, I think for electronic band structures one will have
> the same problem with band ordering -- though most of time people are only
> interested about those very few bands near Fermi level. I wonder in the
> case of electronic band structure whether continuity of wavefunction should
> be used to deal with band ordering with band crossing? Thanks a lot!
>
>
The bands.x code already does that, i.e. it sorts the bands using the
overlap of wavefunctions at consequent k-points. Again, this is an option
that works well for line plots, but I'm not sure it always make sense to
use in a 3D dispersion. Or at least, it would need to be modified to sort
according to neighboring points, not just according to the previous point
in the input list. It is not very hard to do, but a bit boring as it
requires a rethinking of the code structures.

bests

-- 
Dr. Lorenzo Paulatto
IdR @ IMPMC -- CNRS & Université Paris 6
phone: +33 (0)1 44275 084 / skype: paulatz
www:   http://www-int.impmc.upmc.fr/~paulatto/
mail:  23-24/4é16 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05
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