[Wien] Convergence Problem

Tue May 2 13:37:08 CEST 2023

Dear Prof. Dr. Blaha and Prof. Dr. Marks,

Thank you for your valuable solutions,
I'm using WIEN2k 21 version,

In 200 iterations, Grep :GAP case.scf, it is all 0 value.
in inm_tau file;
0.40            mixing FACTOR for BROYD/PRATT scheme
grep :DIS values are oscillating as you can see below it's graph.
[image: image.png]

I tried 0.20 and 0.10 for mixing FACTOR for BROYD/PRATT scheme

With 0.20;

  cycle 200   (Tue Apr 25 23:32:15 +03 2023)  (1/98 to go)

:ENERGY convergence:  1 0.00001 .0000022000000000

:CHARGE convergence:  0 0.0001 .0017906

>   charge in SCF NOT CONVERGED

>   stop
[image: image.png]

With 0.1;

cycle 200   (Tue Apr 25 23:26:47 +03 2023)  (1/98 to go)

:ENERGY convergence:  1 0.00001 .0000034700000000

:CHARGE convergence:  0 0.0001 .0042401

>   charge in SCF NOT CONVERGED

>   stop

[image: image.png]

You can find below my mBJ calculation steps that i've done , is there any
mistakes in my calculation steps?

1. I've made scf calculations with exchange correlation pot. PBEsol and it
converged for ec:0.00001 and cc:0.0001 parameters
2. I have created a new directory called scf_mbj and copied the directory
where the scf files located this directory.
3. I used these commands respectively ;
4. init_mbj
5. runsp_lapw -i 1 -NI
6. save_lapw PBEsol
7. init_mbj_lapw
8. I choose 1, mBJ (for bulk solids)
9. I choose 0, original mBJ
10. runsp_lapw -i 200 -cc 0.0001 -ec 0.00001

Your suggestions are valuable for me ,
Thanks in advance

Laurence Marks <laurence.marks at gmail.com>, 25 Nis 2023 Sal, 12:39 tarihinde
şunu yazdı:

> In addition to what Peter said:
>
> * Please read carefully
>
> http://www.numis.northwestern.edu/Presentations/DFT_Mixing_For_Dummies.pdf
>
> * Why are you trying to converge ee to 0.00001? This may be too small to
> be useful.
>
> * The most common reason for convergence problems is a bad problem, for
> instance RMTs too small, confused au for Angstroms.
>
> * What version are you using? With a recent one did you uncomment "STIFF"?
>
> * Check-mixing is much more useful than what you provided.
>
> --
> Professor Laurence Marks (Laurie)
> Department of Materials Science and Engineering, Northwestern University
> www.numis.northwestern.edu
> "Research is to see what everybody else has seen, and to think what nobody
> else has thought" Albert Szent-Györgyi
>
> On Tue, Apr 25, 2023, 04:23 Peter Blaha <peter.blaha at tuwien.ac.at> wrote:
>
>> Please check the relevant quantity. For a mbj calculation this is usually
>> the gap.
>>
>> grep :GAP case.scf
>>
>> Is it converged and stable ?
>>
>> Also monitor   :DIS how it changes (smooth or with jumps or with
>> long-term slow oszillations?), which may give further hints.
>>
>> mBJ calculations sometimes converge quite difficult, because the kinetic
>> energy density (tausum) is mixed separately using PRATT and the density
>> mixing (using MSR1) may be confused because it does not know about the
>> tausum. In addition there is a "3rd mixing" in lapw0 (potential mixing,
>> which depends on the "greed" of the last cycle - which cannot be changed by
>> an input)
>>
>> Sometimes it helps to:
>>
>> i)  change the mixing factor in case.inm_tau  ( even larger when
>> convergence is slow but smooth, smaller when oszillating !)
>>
>> ii) change for a couple of iterations (maybe 20) to PRATT in case.inm,
>> then continue again with MSR1
>>
>>
>> Am 25.04.2023 um 11:01 schrieb Hülya Gürçay:
>>
>>  Dear Prof. Dr. Blaha and WIEN2k users,
>>
>> I've been using Wien2k since 4 months. I am a physics master's student,
>> calculating the magnetic and thermoelectric properties of quaternary
>> Heusler compounds. I have a question,
>>
>> Energy and charge converged with PBEsol but not with PBEsol-mbj potential
>> .
>>
>> Xc potential : PBEsol - mbj
>> cc: 0.0001
>> ec: 0.00001
>> kmesh:20,20,20
>>
>> Below I am sharing the results got after 100, 150 and 200 iterations.
>>
>>     cycle 100 <>(Sat Apr 22 21:59:29 +03 2023) >(1/99 to go)
>> :ENERGY convergence:  0 0.00001 .0001018050000000
>> :CHARGE convergence:  0 0.0001 .0079100
>> >   energy in SCF NOT CONVERGED
>> >   stop
>>
>>     cycle 150 <>(Sat Apr 22 23:24:49 +03 2023) >(1/49 to go)
>> :ENERGY convergence:  1 0.00001 .0000068950000000
>> :CHARGE convergence:  0 0.0001 .0032008
>> >   charge in SCF NOT CONVERGED
>> >   stop
>>
>>     cyle 200 <>(Sun Apr 23 00:47:57 +03 2023) >(1/98 to go)
>> :ENERGY convergence:  1 0.00001 .0000027900000000
>> :CHARGE convergence:  0 0.0001 .0021041
>> >   charge in SCF NOT CONVERGED
>> >   stop
>>
>> What should I do to get convergence? Please give your valuable suggestions
>>
>> BestRegards,
>> Hülya
>>
>> _______________________________________________
>> Wien mailing listWien at zeus.theochem.tuwien.ac.athttp://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
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>>
>> --
>> -----------------------------------------------------------------------
>> Peter Blaha,  Inst. f. Materials Chemistry, TU Vienna, A-1060 Vienna
>> Phone: +43-158801165300
>> Email: peter.blaha at tuwien.ac.at
>> WWW:   http://www.imc.tuwien.ac.at      WIEN2k: http://www.wien2k.at
>> -------------------------------------------------------------------------
>>
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