| Abstract
| - Normal vibration calculations were performed on 164 basic organic and inorganic compounds by the densityfunctional method of B3LYP/6-311+G** using the wavenumber-linear scaling (WLS) method, in whichessentially only one parameter is involved for the whole wavenumber region. The average deviation of theWLS-scaled calculated wavenumbers from the observed wavenumbers for a total of 1223 normal modes was3.4%. The present results and the previous results on 205 compounds have shown the high performance ofthe WLS method in vibrational analysis of a variety of compounds. The effect of anharmonicity on the observedwavenumbers was examined on the basis of the calculated wavenumbers for 224 diatomic molecules andions in comparison with their experimental harmonic wavenumbers. The results indicate that the larger positivedeviations of the unscaled calculated wavenumbers from the observed values at higher wavenumbers areattributed almost exclusively to the neglect of anharmonicity in the calculated wavenumbers. To generalizeand simplify the WLS method for more convenient use, the wavenumber-linear scale factors were derivedfrom 17 well-defined wavenumbers of liquid indene at different calculation levels. The application of thederived scale factors to vibrational analysis of all-trans-1,3,5,7,9-decapentaene yielded results in close agreementwith the experimental data. This WLS indene calibration method is a convenient technique to obtain vibrationalwavenumbers of large molecules with high accuracy.
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