[Pw_forum] problem regrading convergence

[bramha pandey]

Thank you very much Dear Sir Lorenzo Paulatto and Layla for your kind help.

it was converged in 23 iteration when i put smearing with degauss 0.001,
mixing beta=0.3 with mixing mode = plain.
Sir i wondered my system is semiconductor in nature so how much smearing
should i take?

Also i got mixing mode with 'TF' and 'Local-TF' with 'highly homogeneous'
and 'highly non homogeneous'  system respectively. so how can one decide
when we should use it?
i know this is very trivial  question which i was asking due to my less
knowledge in this field.

Thanks in advanced.

On Sun, Apr 15, 2012 at 11:08 PM, Lorenzo Paulatto <
Lorenzo.Paulatto at impmc.upmc.fr> wrote:

> On Sun, 15 Apr 2012 11:50:18 +0200, bramha pandey
> <pandey.bramha at gmail.com> wrote:
> > LiInTe2
>
> If this crystal is metallic, at least in DFT and at the specific unit cell
> volume you are using, it will probably not converge without a smearing.
>
> > mixing_beta = 0.8
>
> If you have problems with convergence you should *reduce* not increase
> this parameter (take something like 0.3)
>
> >  diagonalization = 'cg',
>
> this controls the diagonalization performed at each scf step, not the scf
> step iteself, use the default algorithm instead wich is faster.
>
> bests
>
>
> --
> Lorenzo Paulatto IdR CNRS @ IMPMC/UPMC - Paris 6
> phone: +33 (0)1 44275 084 / skype: paulatz
> www:   http://www.impmc.upmc.fr/~paulatto/
> mail:  23-24/4é14 Boîte courrier 115, 4 place Jussieu 75252 Paris Cédex 05
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-- 
Thanks and Regards
Bramha Prasad Pandey
GLA University, Mathura.
INDIA.
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