[Wien] Problems in convergence due to application of mBj potential
Luis Carlos Ogando Dacal
ogando at ieav.cta.br
Thu Aug 30 18:45:51 CEST 2012
Dear Prof. Blaha, Marks and WIEN2k community,
I will try the second option ("to use MSR1a and mBJ (without SO)
and check how much the structure changes").
As soon as possible, I will report the results.
All the best,
Luis
2012/8/30 Laurence Marks <L-marks at northwestern.edu>:
> I think using mBJ and MSR1a is the idea -- is it valid/better compared
> to just mBJ with PBE refined positions? I think it might be, but it is
> hard to say.
>
> And, of course, without -so.
>
> On Thu, Aug 30, 2012 at 8:48 AM, Peter Blaha
> <pblaha at theochem.tuwien.ac.at> wrote:
>> Once again:
>>
>> Do you mean MSR1 or MSR1a ???? The little "a" makes a big difference
>> and you can only compare PRATT and MSR1 for mBJ, but not MSR1a.
>>
>> Of course, a second try could be to use MSR1a and mBJ (without SO) and
>> check how much the structure changes.
>>
>>> performance of MRS1a and PRATT when using mBJ in the band structure
>>> calculation (as described in section 4.5.9 of the WIEN_12 Users
>>> Guide). So, I was trying to improve the band gap and spin splittings
>>> of the system (not to relax it) with mBJ, this is the reason why I
>>> switched the -so option in this calculation (but not in the previous
>>> structure optimization for the reasons you described).
>>> Now, I know that MSR1a try to optimize the structure, what means it
>>> is not an ordinary SCF cycle, so SOC is an unappropriated option as
>>> you posted. I am sorry for the misunderstanding.
>>> I will try a new structure optimization using MSR1a-mBJ with the
>>> same parameters employed in the MSEC1-PBE case, allowing a fair
>>> comparison between their performances. I promise to report the result
>>> as soon as possible.
>>> Thank you for your attention,
>>> Luis
>>>
>>>
>>>
>>> 2012/8/30 Peter Blaha <pblaha at theochem.tuwien.ac.at>:
>>>> For sure, forces are NOT ok when you switch on spin-orbit coupling.
>>>>
>>>> But please: think about the physics: InP is not that heavy and is a
>>>> semiconductor. You do NOT need SO for any structural relaxation as
>>>> it has negligible effects anyway.
>>>> (However, you may NEED SO for bandstructure properties, effective
>>>> masses,....,
>>>> but calculate this afterwards with fixed positions, NEVER with MSR1a but
>>>> with MSR1).
>>>>
>>>>
>>>> Furthermore, in your mail it sounds as if you mixed up various schemes
>>>> with WIEN2k.
>>>>
>>>> When using MSR1 you do NOT optimize positions (only "electrons"),
>>>> MSR1a you ALWAYS will optimize positions (in fact, when you do
>>>> not
>>>> have case.inM, it will be generated automatically !)
>>>>
>>>> And for both schemes you use the command run_lapw !
>>>>
>>>> Alternatively, you can use min_lapw (and MSR1, not MSR1a), which will
>>>> also optimize positions (and if case.inM does not exist, will generate
>>>> it automatically).
>>>>
>>>> Both, MSR1a or min_lapw accept "constraint positions", when you execute
>>>> x pairhess -copy (creates case.inM)
>>>> edit case.inM and set some values to zero for constraining them.
>>>> x pairhess -copy (so that the constrains are honored in the hessian for
>>>> PORT).
>>>>
>>>> PS: At least for insulators (but usually even for difficult 3d-metallic
>>>> systems)
>>>> I strongly recommend MSR1a over min_lapw, as it is almost always much
>>>> faster and more stable. The only problem left is to determine a unique way
>>>> when to stop MSR1a (this means: what stopping criteria one should use),
>>>> but when you accept some remaining forces (less than 5 mRy/bohr),
>>>> even this is not a serious problem and default criteria (or even a bit
>>>> larger value than 2.0 in case.inM) are sufficient and reasonable.
>>>>
>>>> PPS: When one tries MSR1a together with mBJ, I'd first converge mBJ (at
>>>> least
>>>> partly) with MSR1 (or PRATT and later on MSR1), and then remove case.in0_grr
>>>> (this will fix the value of "c" in mBJ and make things for MSR1a more
>>>> stable).
>>>>
>>>>
>>>> Am 29.08.2012 19:03, schrieb Luis Carlos Ogando Dacal:
>>>>
>>>>> Dear Prof. Laurence Marks,
>>>>>
>>>>> Let me answer you using your previous message.
>>>>>
>>>>>> First, a reminder. Using MSR1a with mBJ is a computational experiment.
>>>>>> It may not give reasonable results, or it might -- I do not know and I
>>>>>> am not sure that anyone does, yet. The "standard" method is not to
>>>>>> vary the atomic positions with mBJ, but this may not be optimal.
>>>>>
>>>>>
>>>>> Yes, I know. I just tested MSR1a as you asked the WIEN mailing list
>>>>> in a message you sent in August, 22. I will keep on the calculation
>>>>> using the standard and reliable methods. My report was just a little
>>>>> contribution to your efforts.
>>>>>
>>>>>> One thing to check, in your case what are the positions like in the
>>>>>> substrate? Assuming that you have made this thick enough (e.g. 20 au
>>>>>> or more) in the center the positions should be close to those with PBE
>>>>>> and/or the bulk. If they are wildly different this implies that the
>>>>>> bulk lattice parameters for PBE do not match well those from mBJ. (Of
>>>>>> course, if you have only used 2 layers or so of substrate you cannot
>>>>>> test this.)
>>>>>
>>>>>
>>>>> Actually, I did not optimized the structure using MSR1a. I did it
>>>>> in a previous calculation with MSEC1 and PBE with case.inM fixing the
>>>>> substrate positions. Only after that, I used mBJ to improve the gap.
>>>>> When I employed mBJ with PRATT (0.2 followed by 0.4 mixing factors) I
>>>>> got the convergence in the SCF cycle and a smooth decrease in ETEST.
>>>>> In the MSR1a test, I noticed abrupt changes in ETEST and after the
>>>>> last iteration I got the message "energy in SCF NOT CONVERGED".
>>>>> As I was not optimizing the structure when using MSR1a, I had not a
>>>>> case.inM file and all the atoms changed position during MSR1a
>>>>> calculations. Despite the fact that I used a thin substrate (I will
>>>>> improve this in a next step), the atomic positions changed only by a
>>>>> factor of 10^(-3) when compared to the previously PBE relaxed
>>>>> structure (It is important to remember that MSR1a did not converged
>>>>> and I used the last generated case.struct to compare with PBE relaxed
>>>>> structure)
>>>>>
>>>>>> When you say "it did not converge with MSR1a", what exactly do you
>>>>>> mean? It may be better to send the case.struct and case.scf files to
>>>>>> my email directly.
>>>>>
>>>>>
>>>>> I was talking about the message at the end of the MSR1a calculation
>>>>> ("energy in SCF NOT CONVERGED"). I have not calculated any physical
>>>>> property of the system.
>>>>> I will send you the files in another message.
>>>>>
>>>>>> If you fix some atoms in case.inM, then the ones which are not fixed
>>>>>> will move. While some people argue that this is OK, I have
>>>>>> reservations. If you fix all the atoms in case.inM then MSR1a will
>>>>>> crash on you -- you have to use MSR1 (or MSEC3).
>>>>>
>>>>>
>>>>> All the best,
>>>>> Luis
>>>>>
>>>>>
>>>>>
>>>>>> On Wed, Aug 29, 2012 at 7:50 AM, Luis Carlos Ogando Dacal
>>>>>> <ogando at ieav.cta.br> wrote:
>>>>>>>
>>>>>>> Dear Prof. Laurence Marks (and WIEN2k users),
>>>>>>>
>>>>>>> I would like to report my recent experience in using MSR1a with
>>>>>>> mBJ. I have a semiconductor system composed by In and P atoms that I
>>>>>>> relaxed using PBE. After that, I tried the mBJ SCF cycle using PRATT
>>>>>>> as recommended in section 4.5.9 of the WIEN Users Guide. I got the
>>>>>>> convergence after a long cycle (strict convergence criteria), but no
>>>>>>> convergence was obtained with MSR1a.
>>>>>>> If you want any detail of my system and/or calculation, just send
>>>>>>> me an e-mail.
>>>>>>> Another point, my system tries to simulate a substrate and a cap
>>>>>>> stressed layer. As a consequence, I need to fix the substrate atoms
>>>>>>> during the SCF cycles. I would like to know if this can be done with
>>>>>>> case.inM when using MSR1a (or any other way). I believe that fixing
>>>>>>> atoms leads MSR1a to behave like MSR1. Is this right ?
>>>>>>> All the best,
>>>>>>> Luis Ogando
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> 2012/8/22 Laurence Marks <L-marks at northwestern.edu>:
>>>>>>>>
>>>>>>>> I am sure Peter had a typo - I think he meant MSR1 not MSR1a. Whether
>>>>>>>> MSR1a
>>>>>>>> is a good idea with mBJ is currently unclear; there was a recent
>>>>>>>> discussion
>>>>>>>> of this, look in the email archives.
>>>>>>>>
>>>>>>>> A good topic where readers of this list could contribute is testing
>>>>>>>> whether
>>>>>>>> MSR1a with mBJ is physically reasonable and reporting back.
>>>>>>>>
>>>>>>>> On Aug 22, 2012 8:47 AM, "Madhav Ghimire" <ghimire.mpg at gmail.com>
>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> Dear Prof. Marks,
>>>>>>>>> Thank you very much for replying immediately. I was just replying
>>>>>>>>> to
>>>>>>>>> your post.
>>>>>>>>> As in userguide of wien2k, it is suggested to edit the case.inm and
>>>>>>>>> change
>>>>>>>>> MSR1a with PRATT as MSR1a leads to convergence problems in mBj. Hence,
>>>>>>>>> I
>>>>>>>>> performed the calculations by changing MSR1a with PRATT.
>>>>>>>>> I will follow to what you suggest right now and report within a day or
>>>>>>>>> two.
>>>>>>>>> Please let me know more if I have to be cautious somewhere in the
>>>>>>>>> calculations.
>>>>>>>>> Thanks.
>>>>>>>>> Madhav
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> On Wed, Aug 22, 2012 at 8:21 PM, Laurence Marks
>>>>>>>>> <L-marks at northwestern.edu>
>>>>>>>>> wrote:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> Can you send the case.scf file to me directly? I am curious why MSR1
>>>>>>>>>> does
>>>>>>>>>> not converge well for some mBJ and there are some things printed in
>>>>>>>>>> case.scfm which may explain.
>>>>>>>>>>
>>>>>>>>>> ---------------------------
>>>>>>>>>> Professor Laurence Marks
>>>>>>>>>> Department of Materials Science and Engineering
>>>>>>>>>> Northwestern University
>>>>>>>>>> www.numis.northwestern.edu 1-847-491-3996
>>>>>>>>>> "Research is to see what everybody else has seen, and to think what
>>>>>>>>>> nobody else has thought"
>>>>>>>>>> Albert Szent-Gyorgi
>>>>>>>>>>
>>>>>>>>>> On Aug 21, 2012 9:50 PM, "Madhav Ghimire" <ghimire.mpg at gmail.com>
>>>>>>>>>> wrote:
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Dear wien users and developers,
>>>>>>>>>>> I am working on some 3d TM oxides. With a normal scf cycle
>>>>>>>>>>> with or
>>>>>>>>>>> without inclusion of U value, I got good convergence in energy and
>>>>>>>>>>> charge.
>>>>>>>>>>> This oxide material is reported to have a bandgap of approx. 0.3 eV.
>>>>>>>>>>> In GGA,
>>>>>>>>>>> I do not observe any gap. In the meantime even with very high value
>>>>>>>>>>> of U,
>>>>>>>>>>> the bandgap do not open up. Because of this, I tried to implement
>>>>>>>>>>> mBj
>>>>>>>>>>> potential (in order to find the bandgap) both with and without
>>>>>>>>>>> inclusion of
>>>>>>>>>>> U, but the energy and charge do not converge.
>>>>>>>>>>> Rather even for a large number of iteration (199), the energy and
>>>>>>>>>>> charge
>>>>>>>>>>> remains constant without convergence (shown below).
>>>>>>>>>>>
>>>>>>>>>>> For GGA without mBj the scf cycle smoothly converges as below:
>>>>>>>>>>> in cycle 22 ETEST: .0000236850000000 CTEST: .0038743
>>>>>>>>>>> in cycle 23 ETEST: .0000184300000000 CTEST: .0012996
>>>>>>>>>>> in cycle 24 ETEST: .0000174650000000 CTEST: .0006011
>>>>>>>>>>> in cycle 25 ETEST: .0000037600000000 CTEST: .0007451
>>>>>>>>>>> in cycle 26 ETEST: .0000016050000000 CTEST: .0001163
>>>>>>>>>>>
>>>>>>>>>>>> stop
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> while with mBj+GGA, energy and charge convergence remains constant
>>>>>>>>>>> above cycle 103 and could not converge as below:
>>>>>>>>>>> in cycle 193 ETEST: .2112103950000000 CTEST: 2.0591251
>>>>>>>>>>> in cycle 194 ETEST: .2112103950000000 CTEST: 2.0591251
>>>>>>>>>>> in cycle 195 ETEST: .2112103950000000 CTEST: 2.0591251
>>>>>>>>>>> in cycle 196 ETEST: .2112103950000000 CTEST: 2.0591251
>>>>>>>>>>> in cycle 197 ETEST: .2112103950000000 CTEST: 2.0591251
>>>>>>>>>>> in cycle 198 ETEST: .2112103950000000 CTEST: 2.0591251
>>>>>>>>>>> in cycle 199 ETEST: .2112103950000000 CTEST: 2.0591251
>>>>>>>>>>>
>>>>>>>>>>>> energy in SCF NOT CONVERGED
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> Does anyone have experienced this type of problems. If so, please
>>>>>>>>>>> let me
>>>>>>>>>>> know how it can be converged. I followed all the steps as described
>>>>>>>>>>> in
>>>>>>>>>>> previous wien mail and userguid but could not solve.
>>>>>>>>>>> Your help to solve this issue will be higly appreciated.
>>>>>>>>>>> Thanks in advance
>>>>>>>>>>>
>>>>>>>>>>> Madhav Ghimire
>>>>>>>>>>>
>>>>>>>>>>> --
>>>>>>>>>>> MANA, National Institute for Materials Science (NIMS)
>>>>>>>>>>> 1-1 Namiki, Tsukuba, Ibaraki, Japan
>>>>>>>>>>> Phone: +81-29-851-3354 (ex.4115)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> _______________________________________________
>>>>>>>>>>> Wien mailing list
>>>>>>>>>>> Wien at zeus.theochem.tuwien.ac.at
>>>>>>>>>>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>> --
>>>>>>>>>>> MANA, National Institute for Materials Science (NIMS)
>>>>>>>>>>> 1-1 Namiki, Tsukuba, Ibaraki, Japan
>>>>>>>>>>> Phone: +81-29-851-3354 (ex.4115)
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> _______________________________________________
>>>>>>>>>> Wien mailing list
>>>>>>>>>> Wien at zeus.theochem.tuwien.ac.at
>>>>>>>>>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> --
>>>>>>>>> MANA, National Institute for Materials Science (NIMS)
>>>>>>>>> 1-1 Namiki, Tsukuba, Ibaraki, Japan
>>>>>>>>> Phone: +81-29-851-3354 (ex.4115)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>
>>>>>>>> _______________________________________________
>>>>>>>> Wien mailing list
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>>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Wien mailing list
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>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>> --
>>>>>> Professor Laurence Marks
>>>>>> Department of Materials Science and Engineering
>>>>>> Northwestern University
>>>>>> www.numis.northwestern.edu 1-847-491-3996
>>>>>> "Research is to see what everybody else has seen, and to think what
>>>>>> nobody else has thought"
>>>>>> Albert Szent-Gyorgi
>>>>>> _______________________________________________
>>>>>> Wien mailing list
>>>>>> Wien at zeus.theochem.tuwien.ac.at
>>>>>> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>>>>>
>>>>> _______________________________________________
>>>>> Wien mailing list
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>>>>>
>>>>
>>>> --
>>>>
>>>> P.Blaha
>>>> --------------------------------------------------------------------------
>>>> 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 WWW:
>>>> http://info.tuwien.ac.at/theochem/
>>>> --------------------------------------------------------------------------
>>>>
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>>
>> --
>>
>> P.Blaha
>> --------------------------------------------------------------------------
>> 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 WWW: http://info.tuwien.ac.at/theochem/
>> --------------------------------------------------------------------------
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>
>
>
> --
> Professor Laurence Marks
> Department of Materials Science and Engineering
> Northwestern University
> www.numis.northwestern.edu 1-847-491-3996
> "Research is to see what everybody else has seen, and to think what
> nobody else has thought"
> Albert Szent-Gyorgi
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
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