Dear Dr. Shen,

If there are multiple minima, the optimizer in ADF will usually find
the nearest local minimum (or more precisely: the minimum in which basin
the starting position is located). This local minimum may not be the global
minimum. The ADF optimizer does not differ from most other optimizers in
this respect.

The QM-MM option in ADF has a possibility to check various conformers
to find a global minimum, but this is at a lower level of theory.

It is hard to say in general which local minimum will be found because
this depends on many factors. The starting geometry is of course
a very important factor.

I hope this answers your question sufficiently.

Best regards,
Stan van Gisbergen

> Dear Sir,
> I have a problem which is related to ADF calculations. If a molecular has 2 minima( one is global minimum, the other is local minimum) with the same symmetry(say, C2V), when we optimize its geometry in ADF, will we always get the global minimum as the final optimized geometry? Or it depends on the starting geometry whether we will get the global minimum or local minimum?
> I have been thinking about this for a long time, Can you be kind enough to enlighten me on this?
>
> Thanks a lot.
>
> Yours Sincerely,
> Yinghua shen
 
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Dr. S.J.A. van Gisbergen SCIENTIFIC COMPUTING & MODELLING NV
Phone: +31-20-4447626 Vrije Universiteit, Theoretical Chemistry
Fax: +31-20-4447629 De Boelelaan 1083
E-mail: vangisbergen_at_scm.com 1081 HV Amsterdam, The Netherlands
                               http://www.scm.com
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Received on 2002-11-06 19:18:58