[Wien] a couple questions about minimization

[L. D. Marks]

On Thu, 9 Dec 2004, Shu Miao wrote:

> Dear users,
> I'm running a complex parallel calculation to minimize the
> internal parameters of an H cell. I have two troubles:
> 1. After the scf of each changed structure was done, mini shows the
> following message:
> >>  (mini) PORT stopped -> exit
>  :WARNING, CURVATURE CONDITION FAILED
>  :WARNING, S.Y WAS  -1.9945581246343171E-004
>  :WARNING, MIMIMIZATION MAY BE IN TROUBLE
>
> Nobody in my group can tell too much about it, though they know it's a bad
> thing. Can anyone kindly explain it to me what's it and how to deal with?

	Please see the FAQ
	http://www.wien2k.at/reg_user/textbooks/Optimization-Notes.pdf
	It may not be important
>
> 2. In the final structure, the atom initially sits at (0,0,0) is moved to
> (0,0,0.999). Does this mean I need rebuild the cell with decreased C
> parameter while keeping all the refined inter-atom distances same?
	Are the forces small? If they are, you have converged so you don't
need to worry.
>
> Many thanks
>
> Shu Miao
>
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> Wien mailing list
> Wien at zeus.theochem.tuwien.ac.at
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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
email: L - marks @ northwestern . edu
http://www.numis.northwestern.edu
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