[Wien] LDA+U convergence

[Laurence Marks]

In general, a well-posed physical problem converges rapidly; a poorly
posed one badly if at all. Most probably your system wants to be
spin-polarized, or you have too few k-points, bad RMT's etc. For
certain if you have large oscillations for 0.02 you have constructed
the problem incorrectly -- unless you are doing a single atom which is
different.

On Thu, Jun 26, 2008 at 4:07 PM, Jian-Xin Zhu <jxzhu at lanl.gov> wrote:
> Dear Wien users,
>
> I am running LDA+U calculations for a compound
> by executing
>
> runsp_c_lapw -orb -i 40 -cc 0.0001
>
> and find it hard to converge.
>
> Some of output is pasted below.
>
> in cycle 38    ETEST: .0029925000000000   CTEST: .0092126
>  LAPW0 END
>  ORB   END
>  ORB   END
>  LAPW1 END
>  LAPW2 END
>  LAPW2 END
> LAPWDM END
> LAPWDM END
>  CORE  END
>  CORE  END
>  MIXER END
> in cycle 39    ETEST: .0129470000000000   CTEST: .0161093
>  LAPW0 END
>  ORB   END
>  ORB   END
> ....
>
> The CTEST is oscillating. How can I work around to have it converge?
> Though likely less important, I have tuned down the mixing factor to
> 0.02 in the MSEC1 mode.
> In the case.inorb, I still kept the template setting
> PRATT  1.0                    BROYD/PRATT, mixing
>
>
> Thanks for the help.
>
>
> --
> ################################
> Jian-Xin Zhu, Ph.D
> Theorertical Division, MS B262
> Los Alamos National Laboratory
> Los Alamos, NM 87545
> Phone: (505) 667 2363
> Fax: (505) 665 4063
> Emai: jxzhu at lanl.gov
> URL: http://theory.lanl.gov
> ################################
>
>
>
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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
Commission on Electron Diffraction of IUCR
www.numis.northwestern.edu/IUCR_CED