[Pw_forum] Re:Re:vc-relax (Eric Abel)

Axel Kohlmeyer akohlmey at cmm.chem.upenn.edu
Tue Sep 12 21:34:03 CEST 2006

On 9/12/06, Eric Abel <etabel at hotmail.com> wrote:
> Thank you all for your tips.  It turns out the real fix was to upgrade to
> the latest stable version.  Now the program is behaving as I would expect.
> Cesar, you mention the parameters wmass and dt...I was wondering if there is
> a way to get an initial estimate for these values.  Unfortunately the
> documentation on this is sketchy at best.


please have a look at the tutorial material that cesar recommended, e.g.,
it contains a lot of examples. usually one needs to get 'a feeling' for
what effect the various parameters have, and in the tutorial pages you
have a large number of examples that you can run easily and then
you should modify individual parameters to see how it affects convergence.


> Right now I am running with wmass=0.1, and I didn't set dt, so it must be
> using the default.  Things are converging slowly...the atomic forces are
> creeping down.

> Eric

Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
  Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
If you make something idiot-proof, the universe creates a better idiot.

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