[Pw_forum] ERROR IN PHONON CALCULATION.

[Alcantara Ortigoza, Marisol]

Dear Paolo Gianozzi,

Thanks for replying. I restarted from the very beginning, the scf
calculation with a completely new (empty) temporal output directory,
then I did the non-self-consistent calculation; at the end, it still
showed the warning : " WARNING:     1 eigenvalues not converged " I was
using mixing beta = 0.1 . The output files were there. But the same
error resulted when I ran ph.x

So, I started - again - from the very beginning but this time I changed
the diagonalization method to 'conjugated-gradient' for the
non-self-consistent calculation and no problem about convergency showed
up at the end of the band-structure calculation (I did not care about
forces because of what you said). Anyway, now it is running OK.

Thank you very much.

Marisol Alcantara Ortigoza.  

-----Original Message-----
From: pw_forum-admin at pwscf.org [mailto:pw_forum-admin at pwscf.org] On
Behalf Of Paolo Giannozzi
Sent: Monday, March 07, 2005 4:07 PM
To: pw_forum at pwscf.org
Subject: Re: [Pw_forum] ERROR IN PHONON CALCULATION.


On Monday 07 March 2005 18:59, Alcantara Ortigoza, Marisol wrote:

> I've been trying to calculate phonon frequencies in Cu100 at M point 
> (using 18 atoms). I first did the self-consistent calculation using 
> the relaxed postions of the surface, then a non-self consistent 
> calculation using calculation = 'phonon' and specifying the q-vector 
> in &PHONONS, at this point I got extremely high or even undefined ( 
> ***** ) forces,

forces in this case are meaningless and should not be calculated.

>      from davcio : error #        20
>      i/o error in davcio

Look carefully at the examples (3, 5, 6, 7) of phonon calculations.
Remove everything in the scratch directory and start from the beginning.

Check that both the scf and the non-scf calculations have actually
written their files to the scratch directory.

Paolo
-- 
Paolo Giannozzi             e-mail:  giannozz at nest.sns.it
Scuola Normale Superiore    Phone:   +39/050-509876, Fax:-563513 
Piazza dei Cavalieri 7      I-56126 Pisa, Italy
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