[Wien] Error while running +/- 0.5e calculation

[Laurence Marks]

I remember getting similar numbers some years ago. Even back in 2007
everything was 64 bit etc, so that and mkl are not the issue.

Is the 0.314 value with a GGA rather than LDA? I remember that the U for
GGA+U is smaller, and 0.314 might then be right. Otherwise there is some
error.

___________________________
Professor Laurence Marks
Department of Materials Science and Engineering
Northwestern University
www.numis.northwestern.edu
MURI4D.numis.northwestern.edu
Co-Editor, Acta Cryst A
"Research is to see what everybody else has seen, and to think what nobody
else has thought"
Albert Szent-Gyorgi
On Jan 4, 2015 12:16 PM, "Zhu, Jianxin" <jxzhu at lanl.gov> wrote:

>  Gavin,
>
>  I dug out my constraint LDA calculations for NiO done a few months ago.
> The value of F_eff is 0.4293 Ry. I thought it is quite satisfactory in
> comparison with the value that Madsen and Novak published.
> In my calculation, I used RKmax=5 with a single k-point.
>
>  Jianxin
>
>   From: Gavin Abo <gsabo at crimson.ua.edu>
> Reply-To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at
> >
> Date: Sunday, January 4, 2015 9:55 AM
> To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
> Subject: Re: [Wien] Error while running +/- 0.5e calculation
>
>   Probably, you cannot get the 'same' result (just something close to it).
>
> Madsen and Novak got F_eff = 0.438 Ry [
> http://www.wien2k.at/reg_user/textbooks/Constraint_U.pdf ].  However,
> keep in mind that they wrote this document in 2007, so the calculation was
> likely with a WIEN2k version 7 or 8 [
> http://www.wien2k.at/reg_user/updates/ ].  Maybe, they were using 32 bit
> (probably more predominate at that time).  I expect they were using an
> older ifort/mkl (new at that time, but old today).   So differences in
> things like WIEN2k version, between 32 and 64 bit systems, and libraries
> (mkl, fftw) likely make it not possible to reproduce exactly.
>
> Following the steps in Constraint_U.pdf, I got F_eff = ~0.4408 Ry.  When
> compared to Madsen and Novak's result, the percent error is less then 1 %,
> |(0.441-0.438)/0.438|*100% = 0.68 %).
>
> The percent error in your case seems high (20 %):
>
> F_eff =
> (4*-0.007129869+5*-0.027686778)/9-(4*(-0.332762453)+5*(-0.333786554))/9-0.43229+0.46699
> = 0.349481024
> |(0.349-0.438)/0.438|*100% = 20.3 %
>
> As you can see in the table below, the big differences are coming from
> your :3DD001 and :3D 001 values for NiO_+.50.  So this suggests that the
> problem is with your NiO_+.50 calculation.
>
>
>   NiO_+.50
>
> NiO_+.5-1
>
>
>
> Mine
>
> Yours
>
> Mine
>
> Yours
>
> :FER
>
> 0.4779683788
>
> 0.43229
>
> 0.5182555839
>
> 0.46699
>
> :3DD001
>
> 0.109619395
>
> -0.007129869
>
> -0.291937436
>
> -0.332762453
>
> :3D 001
>
> 0.126211972
>
> -0.027686778
>
> -0.273539538
>
> -0.333786554
>
> On 1/4/2015 4:41 AM, Abed Reg wrote:
>
>   Thank you Mr Gavin for your reply and especially for your interesting
> to my questions.
>
>  I have fixed the error and there was a problem in the structure file. Now
> every thing is ok but i didn't find the same results as in the paper of
> Madsen and novak.
>
>  My results are as follows:
>
>  1/ First result
>
> --- FER -----------
> in  1 files:
> NiO_+.50.scf::FER  : F E R M I - ENERGY(GAUSS-.M.)=   0.43229
> --- 3dd001 -----------
> in  1 files:
> NiO_+.50.scf::3DD001: 3D*                 -0.007129869 Ry
>
>
> 2/ Second result
>
> --- FER -----------
> in  1 files:
> NiO_+.50.scf::FER  : F E R M I - ENERGY(GAUSS-.M.)=   0.43229
> --- 3d -----------
> in  1 files:
> NiO_+.50.scf::3D 001: 3D                  -0.027686778 Ry
>
>
> 3/ Third result
>
> --- FER -----------
> in  1 files:
> NiO_+.5-0.scf::FER  : F E R M I - ENERGY(GAUSS-.M.)=   0.46699
> --- 3dd001 -----------
> in  1 files:
> NiO_+.5-0.scf::3DD001: 3D*                 -0.332762453 Ry
>
>
> 4/ Fourth result
>
> --- FER -----------
> in  1 files:
> NiO_+.5-0.scf::FER  : F E R M I - ENERGY(GAUSS-.M.)=   0.46699
> --- 3d -----------
> in  1 files:
> NiO_+.5-0.scf::3D 001: 3D                  -0.333786554 Ry
>
>
> When i have applied the equation i did'nt find the same result as in the paper
>
>
> My result is U= 0.314 Ry
>
>
> Then i think i have made mistake but i don't know where?
>
>
> My best regards
>
> --
>
>           Mr: A.Reggad
> Laboratoire de Génie Physique
>  Université Ibn Khaldoun - Tiaret
>  Algerie
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://zeus.theochem.tuwien.ac.at/pipermail/wien/attachments/20150104/b8185d69/attachment.html>