[Wien] Problem with geometry minimzation

[Saeed Bahramy]

But I used w2web to create my struct file, and the initial R0 (0.0001)  
was actually the one set by w2web.
And  as far as I know, there was no such a complain during init_lapw.

BTW, thanks again for  your helpful comments and feedbacks,
Saeed Bahramy

On Nov 3, 2010, at 8:16 AM, Peter Blaha wrote:

> w2web sets R0 automatically to a correct value.
> And WIEN2k_10 complains during init_lapw if R0 is too big !
>
> Am 02.11.2010 20:37, schrieb Saeed Bahramy:
>> Dear Laurence,
>>
>> Thanks a lot. That was indeed the reason why I couldn't optimize the
>> atomic positions. Reducing (!) R0 to 0.00001, I could successfully
>> minimize all the forces. Now they're all well below 1.0 mRy/a.u..
>>
>> By the way, you said that my initial R0 was too small, but I had to
>> further reduce it in order to get min_lapw working! Am I picking up
>> wrong R0 for Te!? (UG says it should be between 0.0005 to 0.00005)
>>
>> Thanks again,
>> Saeed Bahramy
>>
>>
>> On Nov 3, 2010, at 3:08 AM, Laurence Marks wrote:
>>
>>> Te, R0 is too small.
>>>
>>> 2010/11/2 Saeed Bahramy <bahramy at riken.jp>:
>>>>
>>>> Ok. From this you can clearly see that E-tot and FGL does not fit
>>>> together.
>>>>
>>>> Smaller forces give less negative E-tot. (At least if forces on  
>>>> other
>>>> atoms
>>>> do not destroy this simple logic) and since PORT minimizes E-tot,  
>>>> it
>>>> finishes,
>>>> although it has non-zero forces.
>>>>
>>>> Well, for those steps the total forces on other atoms are large and
>>>> that's
>>>> the reason why E-tot is less negative. For example in the second
>>>> step, the
>>>> total forces on all atoms are as follows:
>>>> :FGL001: 1.ATOM 0.000000000 0.000000000
>>>> -16.042000000 total forces
>>>> :FGL002: 2.ATOM 0.000000000 0.000000000
>>>> 41.642000000 total forces
>>>> :FGL003: 3.ATOM 0.000000000 0.000000000
>>>> 10.710000000 total forces
>>>> and accordingly in this steps :ENE is the highest.
>>>>
>>>> I'm quite sure that my struct file is correct. The initail
>>>> coordinates (as
>>>> well as lattice parameters) have been taken from experiment. Before
>>>> restarting the min_lapw calculation,
>>>>
>>>> This does not say anything. Is R0 ok ? RMTs set properly ?
>>>>
>>>> R0=0.0001 and RMT=2.5 (for all three atoms). Once again, there is  
>>>> no
>>>> touching between the MT's
>>>>
>>>> I do remove histories (*broyd* and *tmpM files). Below, you can  
>>>> find the
>>>> summary of (one of) my min_lapw calculation:
>>>>
>>>> Is it always like this, or other runs are different ?
>>>>
>>>> I always remove the histories before restarting min_lapw with a new
>>>> case.inM
>>>>
>>>>
>>>> If yes, the problem must be somewhere else and again, without  
>>>> testing
>>>> myself,
>>>> I cannot give more than the "standard hints", although the problem
>>>> may stem
>>>> from something completely different ( Are you using the latest  
>>>> WIEN2k
>>>> version
>>>> and have followed all bug-fixes discussed on the mailing list ?)
>>>>
>>>> My current version of WIEN2K is 10.
>>>> Anyway, using this version of WIEN2K, I have been able to do  
>>>> geometry
>>>> optimization for other systems without any problem.
>>>>
>>>> This almost always means that the user (you) has set the IDFT  
>>>> problem
>>>>
>>>> up incorrectly -- GIGO.
>>>>
>>>> Have you read the optimization notes at
>>>>
>>>> http://www.wien2k.at/reg_user/textbooks/ ? Do you have almost  
>>>> touching
>>>>
>>>> spheres, bad RKMAX, k-points etc?
>>>>
>>>> --
>>>>
>>>> P.Blaha
>>>> --------------------------------------------------------------------------
>>>>
>>>> Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
>>>> Phone: +43-1-58801-15671 FAX: +43-1-58801-15698
>>>> Email: blaha at theochem.tuwien.ac.at WWW:
>>>> http://info.tuwien.ac.at/theochem/
>>>> --------------------------------------------------------------------------
>>>>
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>>>>
>>>
>>>
>>>
>>> --
>>> Laurence Marks
>>> Department of Materials Science and Engineering
>>> MSE Rm 2036 Cook Hall
>>> 2220 N Campus Drive
>>> Northwestern University
>>> Evanston, IL 60208, USA
>>> Tel: (847) 491-3996 Fax: (847) 491-7820
>>> email: L-marks at northwestern dot edu
>>> Web: www.numis.northwestern.edu
>>> Chair, Commission on Electron Crystallography of IUCR
>>> www.numis.northwestern.edu/
>>> Electron crystallography is the branch of science that uses electron
>>> scattering and imaging to study the structure of matter.
>>> _______________________________________________
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>>
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>
> -- 
> Peter Blaha
> Inst.Materialchemie, TU Wien
> Getreidemarkt 9
> A-1060 Vienna
> Austria
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