Evaluation of Force Constants of Plane XY3 Molecules from Vibrational Data

Abstract

All five force constants of the most general harmonic potential field are evaluated for 4 molecules and 4 ions of the plane XY₃ type (symmetry group D_3h) by means of Wilson's F—G matrix method. In the cases where no isotopic data are available, this is made possible by the introduction of an approximation from Heath and Linnett's OVFF treatment. Semiquantitative corrections are made for anharmonicity and for the product rule wherever possible. In the case of BF₃, the results are compared with those of a previous worker.