[Pw_forum] error on phonon calculation (root not converged)

[Eyvaz Isaev]

Dear Paolo,

--- Paolo Giannozzi <giannozz at nest.sns.it> wrote:
> 
> this may actually work, but the problem that shows
> up in  Liping's output is rather strange and nasty. 

> The self-consistent  procedure seems to converge 
> quite nicely: |ddv_scf|^2 goes  down towards the
>threshold, then it starts to go up to crazy
> values. 
Yes, I paid attention to this behaviour. Actually,
recently I had very close situation: for some modes
everything was OK, and next mode also started well,
and then turned out to be crazy. At least in my case,
using small mixing parameter fixed the problem.

I suggest, Liping should keep us informed about the
problem.

Bests,
Eyvaz.

> Why, I don't know, and I am afraid there is
> very little  one can do when this kind of behavior 
> occurs in the  middle  of a long job without any 
> apparent reason


 

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