[Pw_forum] Stress calculation in SCF

[Lorenzo Paulatto]

On Mon, July 6, 2009 19:45, Dimpy Sharma wrote:
>  I want to calculate stress and my calculation is a scf calculation,howevr
>  it is not converged, in the output it is showing that problme in cholesky
>  decomposition.

It means that your pseudopotentials are bad, your lattice parameter is
massively off-shot, or you have used a smearing far too high, or possibley
some other reason. This is one of the most frequently asked question,
please have a look at the mailing list archives:
<http://www.google.com/search?&q=site%3Ademocritos.it+cholesky>



>  as in the manual it is written  that stress can only be calculated
>  if calculation is either vc-md or vc-relax.

Although the wording choice in the manual is a bit ambiguous, this is not
true: you can compute the stress also in a scf calculation, by setting
tstress=.true.

best regards


-- 
Lorenzo Paulatto
SISSA  &  DEMOCRITOS (Trieste)
phone: +39 040 3787 511
skype: paulatz
www:   http://people.sissa.it/~paulatto/



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