[Pw_forum] charge is wrong

[Eyvaz Isaev]

Dear user,

Congratulations, you have "rediscovered" this problem, but it was explained many times in the forum.

Let me try explain in somewhat different way. 
What is the charge density? It is 2\sum_{n,k}|\psi_{n,k}|^2, right?
(n is bands number, and k is number of k-points). Imagine, that you did not include a valence band to this sum, then will you have total number of electrons you expected? The same question if you include more conduction bands to the sum. 
If you can find the right answers then you can fix the problem easily (if you have a look at INPUT_PW file as well).

I can suggest that what you do is a teaching purpose only as there is no B1 PtN exists. There was a paper in PRB stating that B1 structure suggested for PtN was wrong, finally it turned out to be FeS2, not CaF2.

Please also keep in mind that submitting a question to this forum requires specifying your name and affiliation.

-------------------------------------------------------------------
Prof. Eyvaz Isaev, 
Theoretical Physics Department, Moscow State Institute of Steel & Alloys, Russia, 
Department of Physics, Chemistry, and Biology (IFM), Linkoping University, Sweden 
Condensed Matter Theory Group, Uppsala University, Sweden 
Eyvaz.Isaev at fysik.uu.se, isaev at ifm.liu.se, eyvaz_isaev at yahoo.com


--- On Fri, 1/23/09, sezginaydin at gazi.edu.tr <sezginaydin at gazi.edu.tr> wrote:

> From: sezginaydin at gazi.edu.tr <sezginaydin at gazi.edu.tr>
> Subject: [Pw_forum] charge is wrong
> To: pw_forum at pwscf.org
> Date: Friday, January 23, 2009, 3:06 PM
> Dear PWScf users,
> I work on the PtN Rocksalt structure. My input file for
> pw.x as foolowing:
> -------------------------------
> PtN
> 2 atoms, NaCl bulk
> &control
>     calculation='scf'
>     restart_mode='from_scratch',
>     prefix='PtN'
>     pseudo_dir =
> '/home/sezgin/espresso-4.0.1/pseudo',
>     outdir='./'
> /
> &system
>     ibrav = 2, 
>     celldm(1) = 4.4
>     nat= 2, 
>     ntyp= 2,
>     ecutwfc = 20
> /
> &electrons
>     conv_thr = 1.0e-8
>     mixing_beta = 0.7
>     mixing_mode = 'plain'
> /
> ATOMIC_SPECIES
>  N  14.0 N.pw91-van_ak.UPF 
>  Pt 190.0 Pt.pw91-n-van.UPF
> ATOMIC_POSITIONS
>  N 0.00 0.00 0.00 
>  Pt 0.5 0.5 0.5 
> K_POINTS {automatic}
> 3 3 3 0 0 0
> -----------------------------
> 
> when i work pw.x, i get the error:
> 
> WARNING: integrated charge=    14.30000000, expected=   
> 15.00000000
> 
> 
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
>      from electrons : error #         1
>      charge is wrong
> 
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> 
>      stopping ...
> 
> what is the problem?
> thanks for your interest
> 
> 
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