Philosophy of scaling the quantum mechanical molecular force field versus philosophy of solving the inverse vibrational problem

摘要

The peculiarities characterising the traditional approach used in calculational vibrational spectroscopy and the approach based on using scaled quantum mechanical force fields are considered. Some results on the determination of the equilibrium geometry of benzene in both the harmonic approximation and in the approximation taking into account the kinematic and dynamic anharmonicity corrections by solving the inverse vibrational problem are discussed. Using the quantum mechanical force fields of the C2F6 molecule, calculated at three different theoretical levels as an example, the results of the determination of scale factors by different mathematical techniques are compared. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 37]