The ABINIT Users Mailing List ( CLOSED )

[Masayoshi Mikami <mmikami@yk.rim.or.jp>]

Hello,

Please, spare time to check the FAQ, before posting your question:
- Tips to use ABINIT : scfcge : ERROR - Potential-based CG line minimization 
not converged
http://www.abinit.org/ABINIT/Infos/FAQ.html#scfcge

Several other things:
- which kind of pseudopotentials for Zn and O ?
  Troullier-Martins ? HGH ? with (or without) Zn-3d as valence ?
- diemac might be set to smaller value, say around 4 to 5.
  But it may be not relevant ...

In passing, I have noticed one more netiquette after reading your mail...
For Microsoft Outlook* users, in particular:

Please, stick to PLAIN TEXT format, to reduce the size of e-mail as possible.
(if your e-mail do not have any attachment.)

In this case, your e-mail could have been just 2.4 KB in plain text format, 
but it swelled to 30 kB in final form, dueto the HTML format.
In my inbox on my PC, almost 2,000 e-mails for ABINIT, 
and unfortunately not a few e-mails are in HTML format ...
So you can imagine how the plain text format will save our Hard-disk space.
Further, we can remember that not all of us are Microsoft users.
In fact, I prefer to read e-mails on Unix/Mac systems, to avoid possible 
virus for Windows... ;-)

--------------------------------------------------------------------------
HOW TO SEND YOUR E-MAIL in PLAIN TEXT ?

For MS Outlook Express Users:
kindly see the online help... or, for example
http://email.about.com/cs/oetipstricks/qt/et012401.htm
http://email.about.com/cs/oetipstricks/qt/et082301.htm

For MS Outlook Users:
kindly see the online help... or, for example
http://email.about.com/cs/outlooktips/qt/et052902.htm
http://email.about.com/cs/outlooktips/qt/et070203.htm
http://email.about.com/cs/outlooktips/qt/et060702.htm

For Other Mailer Users:
Kindly consult with online HELP on your mailer..., or visit 
http://email.about.com/od/getthemostoutofemail/
and find a solution to send your e-mail as plain text format.
--------------------------------------------------------------------------

Good continuation,
Masayoshi

On Sun, 25 Jul 2004 15:48:20 +0200
"Chun Li " <chun.li@mf.mpg.de> wrote:

> Dear all,
>  
> When I tried to calculate the band structure of ZnO, I found that the
> first step (a SCF density computation) did not converge when I set
> nstep=80, but the second step (a non-SCF band structure calculation)
> converged. However, because the density data used in the second step are
> derived from the first step, so the results could not be reliable. So I
> tried increasing the value of nstep, but after that, the following error
> massage lines are appeared in the end of the log file:
>  
> scfcge : ERROR -
>   Potential-based CG line minimization not converged after 13 restarts.
>   Action : read the eventual warnings about lack of convergence.
>   Some might be relevant. Otherwise, raise nband.
>  
>  leave_new : decision taken to exit ...
> FORTRAN STOP  1
>  
> But when I tried to raise the nband, the same error message still
> appeared. I really don't know how to modify the input file then. Can you
> give me some suggestions? Thanks a lot. (I copied the input file below)
>  
> Best regards.
>  
> Chun Li
>  
>  
> My input file:
> # Crystalline ZnO
> # Computation of the band structure.
> # First, a SCF density computation, then a non-SCF band structure
> calculation.
>  
> ndtset 2
>  
> #Dataset 1 : usual self-consistent calculation
>  
> ngkpt1  3 3 2
> prtden1  1         # Print the density, for use by dataset 2
> toldfe1  1.0d-10
>  
> #Dataset 2 : the band structure
> iscf2    -2
> getden2  -1
> kptopt2  -4
> nband2   24
> ndivk2   8 16 8 16      # 8, 16, 8 and 16 divisions of the 4 segments,
> delimited
>                         # by 5 points.
> kptbounds2  0.0    0.0     0.0  # Gamma point
>             0.0    0.0     1/2  # A point
>             0.0    1/2     1/2  # H point
>             0.0    1/2     0.0  # K point
>             0.0    0.0     1.0  # Gamma point in another cell.
> prtvol2  10
> tolwfr2  1.0d-20
> enunit2  1         
> acell   6.15956186 6.15956186 9.83980322     
> angdeg  90 90 120
> ntypat 2          
> znucl 30 8        
> natom 4           
> typat 1 2 1 2
> xred                 
>    0.0  0.0  0.0     # Triplet giving the REDUCED coordinate of atom
> Zn1.
>    0.0  0.0  0.3820  # Triplet giving the REDUCED coordinate of atom O1.
>    1/3  2/3  1/2     # Triplet giving the REDUCED coordinate of atom
> Zn2.
>    1/3  2/3  0.8820  # Triplet giving the REDUCED coordinate of atom O2.
> #Definition of the planewave basis set
> ecut   32.0         
> #Definition of the SCF procedure
> nstep  100       # Maximal number of SCF cycles
> diemac 9.0