

Frederique,

I assume that you are interested in a harmonic force field. Normally, you need
to do elaborate ab initio calculations to get good force constants. But if you
have a good set of experimental data (IR, Raman; the more isotopomers, the
better), then you can use RAMVIB to quickly fit force constants to observed
vibrational frequencies. Usually, the quality of fit will be much better than
that from ab initio. However, assignments and force constant selection will be
the hard part. RAMVIB has some auxilliary programs to make it easier. It is
available free of charge to academic users at CCL archives:

ftp://www.ccl.net/pub/chemistry/software/SGI/ramvib/

Best regards,
Robert Fraczkiewicz

University of Texas Medical Branch
Galveston, TX 77555

--------------------------------------------------------------------------------

================================================================================
Frederique BARBOSA				Institute for Organic Chemistry
						University of Basel
E-mail : [email-masked]		St. Johanns-Ring 19
phone  : 061/267 11 57				4056 Basel
fax    : 061/267 11 05				Switzerland
================================================================================