[Pw_forum] 60 atom Grain boundary... (Elie Moujaes)

[Elie Moujaes]

Thank you very much for your help. I have just got some few more questions:
 
(1) is changing the mesh in the DOS program means  decreasing DeltaE?
 
(2) Concerning the convergence against smearing, does this mean that one has to decrease degauss (mine is degauss=0.01) to get better results?
 
You will find below a part of the bands input file. 
 
&control
    prefix='GBdensity',
    calculation='bands',
    restart_mode='from_scratch',
    pseudo_dir = '/exp/home/caiapo/emoujaes/espresso/espresso-4.1.3/pseudo/',
    outdir='/exp/home/caiapo/emoujaes/espresso/Moujaes-Results/',
          
 /
 &system    
    ibrav= 0, celldm(1) =1.889725989, nat=60, ntyp= 1, ecutwfc =40.0, ecutrho = 160.D0, occupations='smearing', smearing='mp', degauss=0.01
/
 &electrons
    conv_thr=1.D-5,     
    mixing_beta=0.1D0,
    
 /
  
CELL_PARAMETERS (alat)
  24.064488464   0.000772242   0.000000000
  -0.000547177   6.503051170   0.000000000
   0.000000000   0.000000000   8.470514812
 
     
ATOMIC_SPECIES
 C  12.0107  C.pz-rrkjus.UPF
  
ATOMIC_POSITIONS (angstrom)
C      -11.330758616  -3.527803203   0.000000000
C      -10.659793092  -1.160339161   0.000000000
C      -12.039843315  -7.112619698   0.000000000
C      -12.041158182  -5.732701936   0.000000000
C      -10.941089654  -4.881442842   0.000000000
C      -10.331417950  -2.543878336   0.000000000
C       -8.972994221  -3.016349126   0.000000000
C       -8.181174559  -0.722870888   0.000000000
C       -9.522448653  -6.774832629   0.000000000
C       -9.676361200  -5.364937582   0.000000000
C       -8.645931928  -4.406311082   0.000000000

..........
...........
 
 
Thanks again
 
Elie Moujaes
University of Nottingham
NG7 2RD
UK


 


Date: Wed, 26 Jan 2011 01:42:39 +0900
From: adadadad3018 at gmail.com
To: pw_forum at pwscf.org
CC: dekura at sci.ehime-u.ac.jp
Subject: Re: [Pw_forum] 60 atom Grain boundary... (Elie Moujaes)





Dear Elie Moujaes 




Do you mean that your calculated Fermi-energy in C60 system is not located at which the DOS becomes zero even though you got the reasonable band structure. 


If so, I recommend a check for the convergence of Fermi-energy.
 
For example, 


please check the energy convergence against 


(1) increase of the number of k-points in nscf calculation, after you confirm that the KS energy spectrum is converged sufficiently in SCF calculation (and also should check the convergence against the smearing width)


(2) change in the mesh in DOS calculation.




May be you will get more reliable and better result. 




Hope this helps. 




Best Regards.
Haruhiko Dekura






========================================


Haruhiko Dekura


Postdoctoral Fellow


Senior Research Fellow Center, Ehime University, 2?5 Bunkyo-cho, Matsuyama, Ehime 790-8577, Japan
=====================================





Dear all,

I am trying to get the band structure and the DOS of a Grain boundary system of 60 atoms.

(1) The band structure seems ok but when I am trying to set the Fermi energy to be the reference (i.e at 0) where two bands cross, it is not working i.e. I am still getting that the two bands still cross at a negative value (my Fermi energy is -0.098eV). Why is this happening?

(2) The DOS of the system is not zero at zero energy (maybe this is a consequence of 1) and it is a bit wiggly as well (see graph attached)


Thanks in advance

Regards

Elie Moujaes
University of Nottingham
NG7 2RD
UK

_______________________________________________ Pw_forum mailing list Pw_forum at pwscf.org http://www.democritos.it/mailman/listinfo/pw_forum 		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.quantum-espresso.org/pipermail/users/attachments/20110125/fae4cadc/attachment.html>