# CCL: Geometry symmetrizer code or algorithm?

*From*: Andrey.Bliznyuk]|[anu.edu.au
*Subject*: CCL: Geometry symmetrizer code or algorithm?
*Date*: Tue, 08 May 2007 08:53:38 +1000

Sent to CCL by: Andrey.Bliznyuk^^anu.edu.au
Hi,
Many years ago I looked at the problem in conjuction with Turbomole input
generation,
and it resulted in a program that's still available at http://sf.anu.edu.au/~aab900/
(click on "Symmetrization of Input Coordinates and Determination of
Independent Variables")
Another attemt I know about can be found at: http://www.cobalt.chem.ucalgary.ca/ps/
The idea behind the algorithm is simple: first you use some tolerance factor to
determing
what the symmetry is, then the generators of the point group found are used to
generate
an "improved" set of coordinates. Naturally, it only works for
geometry that its not
too far from symmetrical.
Hope it helps.
Dr Andrey Bliznyuk
ANU Supercomputer Facility
Leonard Huxley Bld.(#56)
Canberra, ACT 0200
Australia