[Wien] sign change in Mini

[L. D. Marks]

I sent a sloppy email (and did not check the UG form properly). I should
have said that ETA is ignored in port. DELTA is used, and in general
should be 1 unless you want to fix some atoms (but don't change it during
a run). How large the steps are is controlled directly by the minimization
code (unless Delta is zero in which case the atom or variable will not
move), the user does not have to try and find "good" values any longer.

On Mon, 16 Aug 2004, Jack London wrote:

> Dear Laurence
>
> Thanks for your kindly answer.
>
> > The UG refers to the (older) newt method and needs
> > to be updated. In the
> > current version of port (soon to be changed) delta
> > is ignored. In general
> > I suggest using 1.0 1.0 1.0 for the 1st three unless
> > you want to constrain
> > an atom position -- don't change it in the middle of
> > a run, leave it be!
>
> I find sentence in the UG about DELTA(1-3),
> "Precondition parameters for PORT (determines the
> size of the first step)", Does it meaning minimization
>
> use DELTA in the first step and ignore it in the
> following steps?
>
> Acoording to your mail, "delta is ignored", so I can
> use any value that I want for delta, change it to any
> value at anytime during the minimization running
> without killing case.tmpM, and never affect on the
> final result, Right?
>
> I am sorry I don't understand "you want to constrain
>  an atom position -- don't change it in the middle of
> a run, leave it be!", do you mean I should use the
> case.inM in the SRC_templates (0.6 0.6 0.6 0.7)
> or the case.inM that I attached in the last mail
> (0.0 0.0 0.0 0.5) for the middle layer atom
> (constrain).
>
> Another problem:
> If the "delta is ignored", maybe Wien2k does not need
> to read it, I don't know how you to control atom's
> step,to make an atom move and constrain an atom
> position.
>
> Thank you very much
>
> Zhang
>
>
>
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-----------------------------------------------
Laurence Marks
Department of Materials Science and Engineering
MSE Rm 2036 Cook Hall
2225 N Campus Drive
Northwestern University
Evanston, IL 60201, USA
Tel: (847) 491-3996 Fax: (847) 491-7820
mailto:L-marks at northwestern.edu
http://www.numis.northwestern.edu
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