Hi,

My earlier correspondence on this subject could give the
impression that ADF fails to detect some point groups
for certain large molecules. This is not the case.

I have now found the source of my problems: When I aligned
the principal axes of the molecule to the coordinate axes,
the X and Y axes were permuted as a result of the procedure
I used, which is not related to ADF. When I had fixed this,
such that the molecule was oriented as required by ADF, the
geometry optimization run nicely under the specified point
group.

Sincerely,

Henning Heiberg-Andersen

On Mon, 6 Sep 2004, Stan van Gisbergen wrote:

> Dear Dr. Henning Heiberg-Andersen,
>
> Are you sure ADF cannot do this?
> If you specify the desired symmetry with low tolerance?
>
> This does require that you follow the ADF symmetry conventions,
> such as z-axis should be main symmetry axis etc.
> So your coordinates should be oriented correctly.
> Perhaps it can help to let ADF first symmetrize your coordinates
> for a lower point group ..
>
> Best regards,
> Stan van Gisbergen
>
> On Sep 6, 2004, at 4:21 PM, Henning Heiberg-Andersen wrote:
>
> >
> > Dear ADF users and developers,
> >
> > OK, I was wrong. I thought ADF could force the coordinates into
> > a realizable higher symmetry during geometry optimization. After
> > some tests, I now see that the input coordinates cannot deviate
> > too much from this symmetry.
> >
> > Does anybody have a code who can force a bunch of coordinates into
> > a specified symmetry?
> >
> > Best regards,
> >
> > Henning Heiberg-Andersen
> >
> >
> >
> > On Fri, 3 Sep 2004, Li, Jun wrote:
> >
> >> Hi, there,
> >>
> >> I used ADF for many years and never seem to experience this kind of
> >> problem. Maybe you can post your coordinates (if appropriate) so that
> >> other users in the list can help to check what went wrong.
> >>
> >> Jun Li
> >> ----------------------------------------------
> >> Jun Li, PhD, Senior Research Scientist II
> >> MS K8-91, P.O. Box 999, 3335 Q Avenue,
> >> Environmental Molecular Sciences Laboratory
> >> Pacific Northwest National Laboratory
> >> Richland, Washington 99352
> >> Tel: (509)376-4354 (O)
> >> Fax: (509)376-0420 (O)
> >> E-mail: jun.li_at_pnl.gov
> >> Web: http://emslbios.pnl.gov/id/li_j
> >> ----------------------------------------------
> >>
> >>
> >>
> >> -----Original Message-----
> >> From: owner-adf-list_at_scm.com [mailto:owner-adf-list_at_scm.com] On Behalf
> >> Of Henning Heiberg-Andersen
> >> Sent: Friday, September 03, 2004 10:48 AM
> >> To: adf-list_at_scm.com
> >> Subject: ADF-LIST: ADF, point groups and large molecules
> >>
> >>
> >>
> >> Dear ADF users,
> >>
> >> It appears to me that ADF has problems with detecting the symmetry of
> >> large non-planar molecules. No matter how wide tolerance I give, ADF
> >> aborts when I specify the correct point group of the input coordinates
> >> in geometry optimizations.
> >>
> >> Do anybody have a cure for this problem?
> >>
> >> Best regards,
> >>
> >> Henning Heiberg-Andersen
> >>
> >>
> >
> >
> Dr. S.J.A. van Gisbergen      
> Scientific Computing & Modelling NV
> Theoretical Chemistry, Vrije Universiteit
> De Boelelaan 1083
> 1081 HV Amsterdam
> The Netherlands                              
> T: +31-20-4447626    
> F: +31-20-4447629        
> vangisbergen_at_scm.com  
> http://www.scm.com
>
>
Received on 2004-09-14 09:05:12