[Wien] Problem with mixer

[Laurence Marks]

I can only suspect a problem at 40 iterations.

50-70 is a very large number, and normally convergence takes < 30. The
default 0.40 in the mixing is a bit greedy, and 0.3 or 0,2 might be
better. You may also (perhaps more importantly) be incorrectly posing
the physics or using -it when :DIS is small (which can have some
problems and lead to poor convergence),

Do you have a relatively small number of PW's which are > 1D-12
compared to the number of CLM's? If so I think I know why your
convergence is slow but you will have to wait until the next release
unless you are having pathalogical problems and want to test a beta
version.

On 10/22/07, Björn Hülsen <huelsen at fhi-berlin.mpg.de> wrote:
> The error occurred in the 40th iteration.
> But this problem appears somewhat randomly. I had several (order of 50) other calculations running for 50 - 70
>   iterations without it.
>
> Thank you for the hint.
>
> Best regards
> Bjoern
>
> Laurence Marks wrote:
> > On 10/22/07, Björn Hülsen <huelsen at fhi-berlin.mpg.de> wrote:
> >> Dear L .Marks,
> >>
> >> thanks for the code.
> >> But, as I wrote in my first email, I used the default input for the mixer with a history setting of 8.
> >>
> >> MSEC1  0.0   YES  (BROYD/PRATT, extra charge (+1 for additional e), norm)
> >> 0.40            mixing FACTOR for BROYD/PRATT scheme
> >> 1.00  1.00      PW and CLM-scaling factors
> >> 9999  8         idum, HISTORY
> >>
> >> Best regards
> >> Bjoern
> >>
> > I missed that. Did it occur at the 20th iteration, or perhaps the
> > 40th? If it did I think I know what it is. Unfortunately I cannot
> > currently reach my cluster to check. As a patch you can remove the
> > history files (rm *bro*) and run with the option "-r 99999". There is
> > an obsolete option in the runXX_lapw to reset the mixing after some
> > number of iterations which should not be there (with the new mixer)
> > and might be causing problems.
> >
>
> --
> Björn Hülsen
> Fritz-Haber-Institute
> Theory Department
> Faradayweg 4-6
> 14195 Berlin
>
> phone:  +49 30 8413-4863
> email:  huelsen at fhi-berlin.mpg.de
> www:    www.fhi-berlin.mpg.de
> _______________________________________________
> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
> http://zeus.theochem.tuwien.ac.at/mailman/listinfo/wien
>


-- 
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