[Wien] Unable to achieve required force convergence in structure optimization

Kevin Jorissen kevinjorissenpdx at gmail.com
Tue Aug 26 00:01:48 CEST 2014


PS As a long-time Mac user, I strongly advise against making your OS X file
system case sensitive.  The reason is that 99.99% of OSX users don't, so
developers don't bother to treat case correctly in their OS X software.
 You'll run into obscure problems with other (non-WIEN2k) software that
will be nearly impossible to diagnose or solve.  If you do want to go this
route, I'd advise making a separate partition that you only use for WIEN2k
calculations etc., while leaving the main partition (containing the OS and
your other software) as it is now.

But do take all the other, excellent, advise!


Cheers

Kevin Jorissen



On Sun, Aug 24, 2014 at 10:47 PM, Peter Blaha <pblaha at theochem.tuwien.ac.at>
wrote:

> If this is true, you should not be able to do any optimizations (not just
> limited
> to a few mRy/bohr).
> Anyway, for the moment:
>
> grep inM *_lapw
> grep inM SRC_*/*.f
> (and also in w2web if you are using it)
>
> and change inM to inmini.  (You need at least to modify x, run and mixer)
>
> An alternative was discussed in the mailing list, and you can modify your
> OSX
> so hat it becomes cases sensitive.
>
> k-mesh: FIRST do the optimization with a VERY lousy k-mesh. Later on, you
> can still increase it.
> and: For what purpose do you need 1 meV absolute convergence ? You are
> always looking for
> E-differences, thus you have to test the convergence with E-differences !
> and: change RKmax, RMTs, ... and you will get MUCH LARGER changes in E-tot
> !
>
> It is simply "stupid" to do the optimization with such a k-mesh.
>
>
> Am 25.08.2014 04:14, schrieb Hu, Wenhao:
>
>> Dear Peter:
>>
>> I just realized a problem. Because the operation system of my cluster is
>> OSX, it's unable to distinguish case.inm and case.inM. You mentioned I have
>> to change the convergence parameter to a small value in inM file for ending
>> MSR1a mode. Everytime when I do structure optimization, I'm unable to
>> modify the parameter in .inM file.  I'm not very familiar with WIEN2K. Do
>> you have any suggestions on solving this problem?
>>
>> About the kmesh, I want to get an accuracy of 1meV in the total energy,
>> and I compared the convergence of the total energy in unrelaxed supercell
>> with different sizes of kmesh. I found a 7x7x7 kmesh is required to reach
>> that accuracy.
>>
>> I appreciate any suggestions from you.
>>
>> best regards,
>> Wenhao
>> ________________________________________
>> From: Peter Blaha [pblaha at theochem.tuwien.ac.at]
>> Sent: Sunday, August 24, 2014 6:15 AM
>> To: Hu, Wenhao
>> Subject: Re: [Wien] Unable to achieve required force convergence in
>> structure optimization
>>
>> This is even a case which converges very nicely.
>>
>> init -b -sp -numk 100 -ecut -8 -rkmax 5
>> runsp -fc 5     # indicates huge forces (150)
>> runsp -fc 1 with MSR1a  # converges in lt. 60 cycles.
>>
>> My forces are even below 0.2, although in case.inM I used the default of
>> 2.0 for ending the MSR1a mode. (In any case, if you want small forces,
>> you must set
>> this value to a very small value too (eg. 0.1).
>>
>> After a first relaxation you will see that the Ni-Si distances increased
>> a lot
>> and you should restart with larger RMTs for Si.
>>
>> Why would you use a 7x7x7 mesh ? SiC is an insulator and together with the
>> 2x2x2 supercell, at least for a first structural optimization you can do
>> it with eg. 4 k-points in the IBZ (maybe even 1). Of course, one should
>> always
>> check his final results by continuing with a finer k-mesh (and a larger
>> RKmax).
>> But most likely, the small forces will stay pretty small.
>>
>> When you change Ni vs. C manually, you should also change R0 !
>>
>> PS: Once the Ni-Si distances have increased, one should test if
>> spin-polarization
>> (maybe even with LDA+U) results in a magnetic moment on Ni !
>>
>> Am 24.08.2014 01:44, schrieb Hu, Wenhao:
>>
>>> Dear professor Laurence Marks:
>>>
>>> The structure file of my calculation is:
>>> Title
>>> P                           10
>>>                RELA
>>>    16.476906 16.476906 16.476906 90.000000 90.000000 90.000000
>>> ATOM   1: X=0.00000000 Y=0.00000000 Z=0.00000000
>>>             MULT= 1          ISPLIT= 2
>>> C 1        NPT=  781  R0=0.00010000 RMT=   1.86      Z:  6.0
>>> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>>>                        0.0000000 1.0000000 0.0000000
>>>                        0.0000000 0.0000000 1.0000000
>>> ATOM  -2: X=0.50000000 Y=0.00000000 Z=0.00000000
>>>             MULT= 3          ISPLIT=-2
>>>         -2: X=0.00000000 Y=0.50000000 Z=0.00000000
>>>         -2: X=0.00000000 Y=0.00000000 Z=0.50000000
>>> C 2        NPT=  781  R0=0.00010000 RMT=   1.86      Z:  6.0
>>> LOCAL ROT MATRIX:    0.0000000 0.0000000 1.0000000
>>>                        1.0000000 0.0000000 0.0000000
>>>                        0.0000000 1.0000000 0.0000000
>>> ATOM  -3: X=0.50000000 Y=0.50000000 Z=0.00000000
>>>             MULT= 3          ISPLIT=-2
>>>         -3: X=0.50000000 Y=0.00000000 Z=0.50000000
>>>         -3: X=0.00000000 Y=0.50000000 Z=0.50000000
>>> C 3        NPT=  781  R0=0.00010000 RMT=   1.86      Z:  6.0
>>> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>>>                        0.0000000 1.0000000 0.0000000
>>>                        0.0000000 0.0000000 1.0000000
>>> ATOM   4: X=0.50000000 Y=0.50000000 Z=0.50000000
>>>             MULT= 1          ISPLIT= 2
>>> Ni4        NPT=  781  R0=0.00010000 RMT=   2.08      Z: 28.0
>>> LOCAL ROT MATRIX:    1.0000000 0.0000000 0.0000000
>>>                        0.0000000 1.0000000 0.0000000
>>>                        0.0000000 0.0000000 1.0000000
>>> ATOM  -5: X=0.25000000 Y=0.25000000 Z=0.00000000
>>>             MULT=12          ISPLIT= 8
>>>         -5: X=0.75000000 Y=0.25000000 Z=0.00000000
>>>         -5: X=0.25000000 Y=0.75000000 Z=0.00000000
>>>         -5: X=0.75000000 Y=0.75000000 Z=0.00000000
>>>         -5: X=0.25000000 Y=0.00000000 Z=0.25000000
>>>         -5: X=0.75000000 Y=0.00000000 Z=0.25000000
>>>         -5: X=0.25000000 Y=0.00000000 Z=0.75000000
>>>         -5: X=0.75000000 Y=0.00000000 Z=0.75000000
>>>         -5: X=0.00000000 Y=0.25000000 Z=0.25000000
>>>         -5: X=0.00000000 Y=0.75000000 Z=0.25000000
>>>         -5: X=0.00000000 Y=0.25000000 Z=0.75000000
>>>         -5: X=0.00000000 Y=0.75000000 Z=0.75000000
>>> C 5        NPT=  781  R0=0.00010000 RMT=   1.86      Z:  6.0
>>> LOCAL ROT MATRIX:    0.0000000-0.7071068-0.7071068
>>>                        0.0000000-0.7071068 0.7071068
>>>                       -1.0000000 0.0000000 0.0000000
>>> ATOM  -6: X=0.25000000 Y=0.25000000 Z=0.50000000
>>>             MULT=12          ISPLIT= 8
>>>         -6: X=0.75000000 Y=0.25000000 Z=0.50000000
>>>         -6: X=0.25000000 Y=0.75000000 Z=0.50000000
>>>         -6: X=0.75000000 Y=0.75000000 Z=0.50000000
>>>         -6: X=0.25000000 Y=0.50000000 Z=0.25000000
>>>         -6: X=0.75000000 Y=0.50000000 Z=0.25000000
>>>         -6: X=0.25000000 Y=0.50000000 Z=0.75000000
>>>         -6: X=0.75000000 Y=0.50000000 Z=0.75000000
>>>         -6: X=0.50000000 Y=0.25000000 Z=0.25000000
>>>         -6: X=0.50000000 Y=0.75000000 Z=0.25000000
>>>         -6: X=0.50000000 Y=0.25000000 Z=0.75000000
>>>         -6: X=0.50000000 Y=0.75000000 Z=0.75000000
>>> C 6        NPT=  781  R0=0.00010000 RMT=   1.86      Z:  6.0
>>> LOCAL ROT MATRIX:    0.0000000-0.7071068-0.7071068
>>>                        0.0000000-0.7071068 0.7071068
>>>                       -1.0000000 0.0000000 0.0000000
>>> ATOM  -7: X=0.12500000 Y=0.12500000 Z=0.12500000
>>>             MULT= 4          ISPLIT= 4
>>>         -7: X=0.87500000 Y=0.87500000 Z=0.12500000
>>>         -7: X=0.87500000 Y=0.12500000 Z=0.87500000
>>>         -7: X=0.12500000 Y=0.87500000 Z=0.87500000
>>> Si7        NPT=  781  R0=0.00010000 RMT=   1.46      Z: 14.0
>>> LOCAL ROT MATRIX:    0.4082483-0.7071068 0.5773503
>>>                        0.4082483 0.7071068 0.5773503
>>>                       -0.8164966 0.0000000 0.5773503
>>> ATOM  -8: X=0.62500000 Y=0.12500000 Z=0.12500000
>>>             MULT=12          ISPLIT= 8
>>>         -8: X=0.12500000 Y=0.62500000 Z=0.12500000
>>>         -8: X=0.12500000 Y=0.12500000 Z=0.62500000
>>>         -8: X=0.87500000 Y=0.37500000 Z=0.12500000
>>>         -8: X=0.37500000 Y=0.87500000 Z=0.12500000
>>>         -8: X=0.87500000 Y=0.87500000 Z=0.62500000
>>>         -8: X=0.87500000 Y=0.12500000 Z=0.37500000
>>>         -8: X=0.37500000 Y=0.12500000 Z=0.87500000
>>>         -8: X=0.87500000 Y=0.62500000 Z=0.87500000
>>>         -8: X=0.12500000 Y=0.87500000 Z=0.37500000
>>>         -8: X=0.12500000 Y=0.37500000 Z=0.87500000
>>>         -8: X=0.62500000 Y=0.87500000 Z=0.87500000
>>> Si8        NPT=  781  R0=0.00010000 RMT=   1.46      Z: 14.0
>>> LOCAL ROT MATRIX:   -1.0000000 0.0000000 0.0000000
>>>                        0.0000000-0.7071068-0.7071068
>>>                        0.0000000-0.7071068 0.7071068
>>> ATOM  -9: X=0.62500000 Y=0.62500000 Z=0.12500000
>>>             MULT=12          ISPLIT= 8
>>>         -9: X=0.62500000 Y=0.12500000 Z=0.62500000
>>>         -9: X=0.12500000 Y=0.62500000 Z=0.62500000
>>>         -9: X=0.37500000 Y=0.37500000 Z=0.12500000
>>>         -9: X=0.87500000 Y=0.37500000 Z=0.62500000
>>>         -9: X=0.37500000 Y=0.87500000 Z=0.62500000
>>>         -9: X=0.37500000 Y=0.12500000 Z=0.37500000
>>>         -9: X=0.87500000 Y=0.62500000 Z=0.37500000
>>>         -9: X=0.37500000 Y=0.62500000 Z=0.87500000
>>>         -9: X=0.12500000 Y=0.37500000 Z=0.37500000
>>>         -9: X=0.62500000 Y=0.87500000 Z=0.37500000
>>>         -9: X=0.62500000 Y=0.37500000 Z=0.87500000
>>> Si9        NPT=  781  R0=0.00010000 RMT=   1.46      Z: 14.0
>>> LOCAL ROT MATRIX:    0.0000000-0.7071068-0.7071068
>>>                        0.0000000-0.7071068 0.7071068
>>>                       -1.0000000 0.0000000 0.0000000
>>> ATOM -10: X=0.62500000 Y=0.62500000 Z=0.62500000
>>>             MULT= 4          ISPLIT= 4
>>>        -10: X=0.37500000 Y=0.37500000 Z=0.62500000
>>>        -10: X=0.37500000 Y=0.62500000 Z=0.37500000
>>>        -10: X=0.62500000 Y=0.37500000 Z=0.37500000
>>> Si10       NPT=  781  R0=0.00010000 RMT=   1.46      Z: 14.0
>>> LOCAL ROT MATRIX:    0.4082483-0.7071068 0.5773503
>>>                        0.4082483 0.7071068 0.5773503
>>>                       -0.8164966 0.0000000 0.5773503
>>> This is a nickel doped SiC. The central carbon atom is substituted with
>>> a nickel atom. Besides, I removed a NN silicon of the nickel from the
>>> lattice. A 2x2x2 supercell was implemented. And a 7x7x7 k mesh was applied.
>>> I appreciate any suggestions from you.
>>>
>>> Best,
>>> Wenhao
>>>
>>>
>>> Date: Sun, 27 Jul 2014 00:16:39 -0500
>>> From: Laurence Marks <L-marks at northwestern.edu>
>>> To: A Mailing list for WIEN2k users <wien at zeus.theochem.tuwien.ac.at>
>>> Subject: Re: [Wien] Unable to achieve required force convergence in
>>>           structure optimization
>>> Message-ID:
>>>           <CANkSMZCmNj+1a4mYKiLf9qaFw=PWUGfZym4RULt5UkFE5tGxeg at mail.
>>> gmail.com>
>>> Content-Type: text/plain; charset="utf-8"
>>>
>>> There is a file called README in SRC_mixer, and a copy of this is also in
>>> the notes section of the WIEN2k web page.
>>>
>>> Beyond this nobody can help you as you have not provided any details,
>>> e.g.
>>> case.structure, k-points etc.
>>>
>>> ___________________________
>>> Professor Laurence Marks
>>> Department of Materials Science and Engineering
>>> Northwestern University
>>> www.numis.northwestern.edu1-847-491-3996
>>> 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 Jul 26, 2014 7:18 PM, "Hu, Wenhao" <wenhao-hu at uiowa.edu> wrote:
>>>
>>>  Dear all:
>>>>
>>>> I met a problem when I use MSR1a method to determine equilibrium
>>>> structure
>>>> of my lattice. The convergence I want is 0.5mRy/au. But when I check the
>>>> scfm file, the force on some specific atoms can be as large as 2 mRy/au.
>>>> This problem remained even after I repeatedly ran my calculation for
>>>> several times and lower the convergence from 0.5 to 0.2. Can anyone
>>>> give me
>>>> any suggestions?
>>>>
>>>> Thanks in advance.
>>>> Wenhao
>>>> _______________________________________________
>>>> 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
>>>>
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>>>
>> --
>> -----------------------------------------
>> Peter Blaha
>> Inst. Materials Chemistry, TU Vienna
>> Getreidemarkt 9, A-1060 Vienna, Austria
>> Tel: +43-1-5880115671
>> Fax: +43-1-5880115698
>> email: pblaha at theochem.tuwien.ac.at
>> -----------------------------------------
>>
>>
> --
> -----------------------------------------
> Peter Blaha
> Inst. Materials Chemistry, TU Vienna
> Getreidemarkt 9, A-1060 Vienna, Austria
> Tel: +43-1-5880115671
> Fax: +43-1-5880115698
> email: pblaha at theochem.tuwien.ac.at
> -----------------------------------------
> _______________________________________________
> 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 at zeus.theochem.tuwien.ac.at/index.html
>
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