[Pw_forum] dosup and pdosup in pdos_tot file

[Gabriele Sclauzero]

Il giorno 24/set/2010, alle ore 11.31, B. Koa ha scritto:

> 
> Dear Gabriele
> 
> 
>    Many thanks for your answer. I replaced ngauss=-1 by ngauss=0 and now I don't see any negative value. Also, occupations = 'tetrahedra'
>   and  degauss=0.03 have been used for the nscf calculation.

The tetrahedron method is implemented in dos.x, but not in projwfc.x

In order to use the tetrahedra in the calculation of the DOS you must NOT specify degauss in the namelist. The ngauss variable is ignored used  and there should be no negative densities. Please read the documentation.


HTH

GS

> 
>   Truly Yours
>   B. Koa
>   Azad University (Saveh Branch)
>   Iran 
> 
>    
> 
> 
> 
> Dear Koa (please specify your affiliation),
> 
> 
> On 09/22/2010 11:01 PM, B. Koa wrote:
> >
> >    Dear PWScf Users and Gabriele
> >
> >    As I have read in the tutorial_magn.pdf which prepared by Paolo
> > Giannozzi they are too close to each other but not exactly the same as
> > each other and I don't understand the meaning of dosup and pdosup in
> > the pdos_tot file well; but generally I know the definition of DOS and
> > PDOS.
> 
> So it should be easy for you to understand: dosup is the DOS for up-spin
> states, while pdosup is the PDOS for up-spin states. Since you know the
> definitions of DOS and PDOS, you must be able to understand why they are
> not the same and why they can be almost equal in some energy range (the
> agreement is usually better at lower energies).
> 
> 
> > Also some values of dosup and pdosup in the pdos_tot file have
> > negative sign ! (at higher energies ) but there are not such negative
> > sign of dosup in the *.dos file. What do the negative values mean?
> 
> Negative values in the PDOS (and in the DOS as well) may appear if you
> have used a smearing function like the Methfessel-Paxton one. For
> plotting the DOS it is usually more convenient to adopt the gaussian
> smearing (ngauss=0), even if you used a different one in the scf/nscf
> calculations. For computing DOS integrals, instead, you should use the same.
> 
> 
> 
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§ Gabriele Sclauzero, EPFL SB ITP CSEA
   PH H2 462, Station 3, CH-1015 Lausanne

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