[Pw_forum] GIPAW problems

[Zbigniew Lodziana]

Dear Prasenjit & all,

 Thanks for you remark.

Actually with kind help of Emine we did run calculations with occupancies "fixed" and with k-points and this seem to work & help. Thus i wonder if gamma point sampling is an additional limitation?
If this is so it would result in prohibitive system sizes >1000 atoms.. (for other calculations not mentioned in this thread)

I would appreciate clarification of this aspect.

best regards,
Zibi

---------- Original Message -----------
From: Prasenjit Ghosh <prasenjit.jnc at gmail.com> 
To: PWSCF Forum <pw_forum at pwscf.org> 
Sent: Thu, 6 Sep 2012 08:32:45 +0530 
Subject: Re: [Pw_forum] GIPAW problems

> In addition to Emine's response I would also like to mention that occupations='fixed' is available only for calculations with a gamma k-point. So for your case you need to use a supercell. Also when you do the gamma-point calculations, set K_POINT{automatic} with 1  1 1 0 0 0 mesh because gipaw does not work with the gamma-point specific subroutines.
> At least this is the case for version 4.3.2. I do not know whether this has been improved in 5.0
> 
> With regards,
> 
> Prasenjit
> 
> On 5 September 2012 21:51, Emine Kucukbenli <kucukben at sissa.it> wrote:
> Hi all,
> Just to update the forum:
> The problem mentioned in this thread has been solved by the use of
> occupations='fixed' instead of smearing methods.
> This might be a good time to remind interested users that the QE-GIPAW
> implementation is only for insulators for the time being. Although not
> always, but with some compilers, the unexpected insulator+smearing
> input configuration could give wrong results as we have seen here.
> Currently, Davide Ceresoli is updating the code to include metallic
> systems as well, with this development the mentioned 'bug' would no
> more appear starting from the next release.
> Thanks for your feedback!
> -
> emine kucukbenli
> postdoc, epfl, switzerland
> ------- End of Original Message -------
> 
> -- 
> PRASENJIT GHOSH,
> IISER Pune,
> First floor, Central Tower, Sai Trinity Building
> Garware Circle, Sutarwadi, Pashan
> Pune, Maharashtra 411021, India
> 
> Phone: +91 (20) 2590 8203
> Fax: +91 (20) 2589 9790
 
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