From chemistry-request |-at-| ccl.net Tue Jun 25 11:42:21 1991 Date: Tue, 25 Jun 91 10:16 CST From: Andy Holder Subject: Force Constant Calculations To: CHEMISTRY ^at^ ccl.net Status: R 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 -x- at -x- UMKCVAX1 University of Missouri - Kansas City || Internet Addr: aholder.,at,.vax1.umkc.edu Kansas City, Missouri 64110 || Phone Number: (816) 235-2293 =-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=