[Pw_forum] problem in DOS caluclattion

[Gabriele Sclauzero]

That's right. More precisely, when you use fixed occupations, by default pw.x selects 
nbnd=nelec/2. In this way you don't know the eigenvalues for the empty states above the 
gap, so the projwfc.x code cannot compute pdos for energies higher than the top of the 
valence band.
You have to increase nbnd higher than half the number of (valence) electrons and repeat 
the pdos calculation.

HTH

GS

lan haiping wrote:
> Hi,
> You need specify the number of bands when you adopt 'fixed' scheme for 
> insulators.
> 
> Hope it helps
> Regards
> 
> Hai-Ping
> 
> On Thu, Sep 3, 2009 at 3:02 PM, dev sharma <decboy9 at gmail.com 
> <mailto:decboy9 at gmail.com>> wrote:
> 
>     Hi 2 All,
> 
>      I have calculated the band structure of my system  with occupancy
>     =fixed as it is insulator. Then i tried to calculated  LDOS and PDOS
>     of the system using projwfc.x. But when i am plotting my total DOS
>     i.e. the file "prefix.pdos_tot" , i am getting the DOS  only
>     corresponding to valance band. The conduction  band peaks are
>     missing. Means i am getting the
>     # E (eV)  dos(E)    pdos(E)
>     -15.000  0.916E-07  0.915E-07
>     /
>     /
>     7.210  0.585E-04  0.582E-04
> 
>     i.e. the energy range is Emin=-15 to  Emax=7 ev, whereas my input
>     file for projwfc is listed below, where i have given my Emax=15,
>     &INPUTPP
>     prefix='yvo',
>     outdir='/home/physics/work/yvo/temp',
>     ngauss=0,
>     degauss=0.02,
>     DeltaE=0.01,
>     Emin=-15,
>     Emax=15,
>     /
> 
>     Please help. Thankful to all of you.
> 
>     Dev Sharma,
>      University of delhi
> 
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> 
> 
> 
> 
> -- 
> Hai-Ping Lan
> Department of Electronics ,
> Peking University , Bejing, 100871
> lanhaiping at gmail.com <mailto:lanhaiping at gmail.com>, hplan at pku.edu.cn 
> <mailto:hplan at pku.edu.cn>
> 
> 
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