[Pw_forum] electronic DOS for a GB system of 60 atoms

[Lars Matthes]

Dear Elie,

it looks like you have way too few k-points for your nscf calculation. For a
well converged DOS it isnecessary to have sufficient dense k-grid.
By increasing the number of k-points you'll see, that the DOS will
be much smoother, because up to know the 'waves' in your DOS
doesn't seem to be physical, I think they are artificial and a result of a
low
k-sampling.

If the grid is dense enough and your DOS doesn't change anymore you
can also decrease the smearing and improve the behaviour of your spectra
close to the gap.

Hope that helps
Lars





2011/8/2 Elie Moujaes <elie.moujaes at hotmail.co.uk>

>  Dear all,
>
> I am trying to reproduce calculations done on the electronic DOS of a 60
> carbon system. I have got that the DOS is around 0.2 at the Fermi level
> whereas the calculations done previously got that it is exactly zero. In
> addition their curve seems sharper than mine. I used degauss=0.01 in nscf
> and scf calculations. the grid for scf was  4 4 1 whilst it was 9 9 1 for
> nscf. You will find attached the ps file of the DOS. Can anyone advise me on
> that?
>
> Thanks
>
> Elie Moujaes
>
> University of Nottingham
> NG7 2RD
> UK
>
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>


-- 
Lars Matthes
Institut für Festkörpertheorie und -optik
Friedrich-Schiller-Universität Jena
Max-Wien-Platz 1
07743 Jena
Germany

Phone: +49.3641.947163
Mail:  Lars.Matthes at uni-jena.de
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