Force Constant Calculations

Performing force constant calculations on a molecule as small as
   benzene is a relatively simple task with a high quality semi-
   empirical method such as AM1.  The results are also in pretty
   good agreement with experiment.  Whether this will get you what
   need depends on the level of accuracy that you require of the
   numbers.  There is no simple scaling factor for empirical adjust-
   ments as is the case with ab initio methods, but the frequencies
   from these type of calculations are generally good to +- 5-10%.
                               DR. ANDREW HOLDER
 Department of Chemistry              ||  BITNET Addr:   AHOLDER \\at// UMKCVAX1
 University of Missouri - Kansas City ||  Internet Addr: aholder \\at//
 Kansas City, Missouri 64110          ||  Phone Number:  (816) 235-2293