INTERPRETATION AND ACCURATE PREDICTION OF VIBRATIONAL-SPECTRA - A MODIFIED AB-INITIO SCALED QUANTUM-MECHANICAL APPROACH

A novel method is described to obtain a scale factor for each force co nstant in the force constant matrix as a quantitative measure of the s ystematic error in ab initio methods. These scale factors offer a simp le solution to the problem of interpretation and prediction of vibrati onal spectra using the scaled quantum mechanical (SQM) approach. The a dvantages of the method are illustrated using benzene, acrolein, pyrid ine and benzaldehyde as examples. This method also simplifies the trad itional, tedious way of performing normal coordinate analysis. (C) 199 8 Elsevier Science B.V.