[Wien] Regarding mBJ plus U

Wed Mar 9 06:27:18 CET 2016

mBJ works very well for bandgaps of s,p and even 3d electrons. HOwever, 
it is too weak to handle the atomic-like 4f electrons properly.

xxx+U can handle the 4f electrons, but still very often the gap is too 
small (because it is then determined by the "other electrons" in 4f 
compounds), or one would need an unphysically large value of U.

A combination of mBJ+U with a rather moderate U value looks quite good 
in many cases ....

Am 08.03.2016 um 22:37 schrieb Fecher, Gerhard:
> May be it is off-topic, but what is the physics behind mBJ+U ?
> or is that just a question on why a feature of Wien2k does not work as expected ?
>
> Ciao
> Gerhard
>
> DEEP THOUGHT in D. Adams; Hitchhikers Guide to the Galaxy:
> "I think the problem, to be quite honest with you,
> is that you have never actually known what the question is."
>
> ====================================
> Dr. Gerhard H. Fecher
> Institut of Inorganic and Analytical Chemistry
> Johannes Gutenberg - University
> 55099 Mainz
> and
> Max Planck Institute for Chemical Physics of Solids
> 01187 Dresden
> ________________________________________
> Von: wien-bounces at zeus.theochem.tuwien.ac.at [wien-bounces at zeus.theochem.tuwien.ac.at] im Auftrag von Laurence Marks [L-marks at northwestern.edu]
> Gesendet: Dienstag, 8. März 2016 18:20
> An: A Mailing list for WIEN2k users
> Betreff: Re: [Wien] Regarding mBJ plus U
>
> Repeating myself, please run the command I sent. All anyone can do with the information you have provided to date is guess, probably wrong.
>
> On Tue, Mar 8, 2016 at 10:37 AM, sikander Azam <sikander.physicst at gmail.com<mailto:sikander.physicst at gmail.com>> wrote:
> Dear Laurence Marks<https://plus.google.com/u/0/115978139881852385108?prsrc=4>
> Thanks for your reply, Sir, actually we did mBJ+U calculations for parent compound. We got the convergence. Then we produce the vacancies in the parent compound, for that when we run the mBJ+U we get this problem i.e. the energy is not converged.
> So this is the only worry that why our calculations is not converging. Firstly we give 60 cycles, then 80, but this also didn't solve our problem i.e. we didnt got the convergence.
>
>
> Note: By grep :DIS *.scf we get 0.21815 0.21815 0.21815 ..........20 times
> and by grep :ENE *.scf we get 0.5014 0.5014 .............................20 times
>
> with best regard
> Azam
>
>
>
>
> On Tue, Mar 8, 2016 at 6:31 AM, Laurence Marks <L-marks at northwestern.edu<mailto:L-marks at northwestern.edu>> wrote:
> Please run the command below and post the result; it will provide some information about what is going on (although it may not answer everything). You can either run it in a linux shell (under bash) or paste it to a file (e.g. ~/bin/Check, $WIENROOT/Check or $WIENROOT/Check_lapw), do a "chmod a+x file" then just do "Check" (or whatever name you used).
>
> tail -n 100000 *.scf $1 | grep -e :ADIST -e :DIR -e :MV -e GREED -e :FRMS -e :ENE -e :CHARG -e PRATT \
> -e :DIS -e "MIXING SC" -e ":RANK" -e PLANE | \
> grep -v -e "with 1.0" -e scheme -e CONTRIBUTION | \
> tail -n 50
>
>
> On Tue, Mar 8, 2016 at 8:17 AM, sikander Azam <sikander.physicst at gmail.com<mailto:sikander.physicst at gmail.com>> wrote:
>
> Dear Gavin abin
> Thanks Sir for the reply, but I ran it for 60 cycle two times with commands
> runsp-lapw -p -orb -ec 0.0001 -cc 0.0001 -i 60
> Regards
> Sikander
>
> On 8 Mar 2016 14:36, "Gavin Abo" <gsabo at crimson.ua.edu<mailto:gsabo at crimson.ua.edu>> wrote:
> How many cycles did the calculation run for and what did you set for the maximum number of iterations (i.e., the number that you set for the -i option)?
>
> If you did not use the -i option, just
>
> run_lapw or runsp_lapw
>
> The program will run up to 40 cycles by default.
>
> It is common for a mBJ calculation to not be able to reach converge within 40 cycles [1-3], which is why it suggests during the running of init_mbj that you increase the maximum number of interactions.  The example the init_mbj script gives is to set -i to 80:
>
> run_lapw -i 80 (or runsp_lapw -i 80)
>
> [1] http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg06119.html
> [2] http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg09879.html
> [3] http://www.mail-archive.com/wien%40zeus.theochem.tuwien.ac.at/msg02833.html
>
> On 3/8/2016 3:51 AM, sikander Azam wrote:
>
> Dear all
> I am doing calculations using mBJ plus U, but when the calculations complete, I get that energy is not converged. But when I check the SCF file I get a constant value of 0.52341000 for energy convergence and 0.345680000 values for charge convergence.
> So I don't understand on the logic. please help me that what should I do. Should I continue with these calculations and find the properties or some one will give me some suggestions.
> Thanks in advance.
> Regards
> Azam
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at<mailto:Wien at zeus.theochem.tuwien.ac.at>
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>
>
>
> --
> Professor Laurence Marks
> "Research is to see what everybody else has seen, and to think what nobody else has thought", Albert Szent-Gyorgi
> www.numis.northwestern.edu<http://www.numis.northwestern.edu> ; Corrosion in 4D: MURI4D.numis.northwestern.edu<http://MURI4D.numis.northwestern.edu>
> Partner of the CFW 100% program for gender equity, www.cfw.org/100-percent<http://www.cfw.org/100-percent>
> Co-Editor, Acta Cryst A
>
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at<mailto:Wien at zeus.theochem.tuwien.ac.at>
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>
>
>
>
>
> --
> Professor Laurence Marks
> "Research is to see what everybody else has seen, and to think what nobody else has thought", Albert Szent-Gyorgi
> www.numis.northwestern.edu<http://www.numis.northwestern.edu> ; Corrosion in 4D: MURI4D.numis.northwestern.edu<http://MURI4D.numis.northwestern.edu>
> Partner of the CFW 100% program for gender equity, www.cfw.org/100-percent<http://www.cfw.org/100-percent>
> Co-Editor, Acta Cryst A
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
> SEARCH the MAILING-LIST at:  http://www.mail-archive.com/wien@zeus.theochem.tuwien.ac.at/index.html
>

-- 
--------------------------------------------------------------------------
Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-165300             FAX: +43-1-58801-165982
Email: blaha at theochem.tuwien.ac.at    WIEN2k: http://www.wien2k.at
WWW:   http://www.imc.tuwien.ac.at/staff/tc_group_e.php
--------------------------------------------------------------------------