Scaled quantum mechanical computations of vibrational spectra of organoelement molecules, containing the atoms P, S, and Cl

Density functional theory has been used for the calculation of vibrational force fields of organoelement molecules. Optimal scaling factors for various stretching and bending force constants are derived from a training set of 12 molecules, containing H, C, N, O, P, S, and Cl atoms, and used to scale force constants for further 14 molecules. These 13 scaling factors, applied to B3LYP force fields, allow compute the 310 frequencies of 26 molecules with the total standard deviation of about 11 cm(-1) for 6-31G* and 6-31+G* basis sets, the latter set being preferable for computations of Raman spectra. (C) 2003 Elsevier B.V. All rights reserved.