[Wien] Problem with geometry minimzation

[Laurence Marks]

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.