Kinematical evaluation of force constants: application to trihalides of phosphorus and arsenic

Abstract

The F-matrix elements for the two-dimensional symmetry species are dependent on one arbitrary parameter in addition to the vibrational frequencies. This parameter has been chosen as an angle ø (0 ≤ ø ≤ 2π) and the F-matrix elements for the A₁- and the E-species of trihalides of phosphorus and arsenic have been studied as functions of ø. It is found that the best values of the force constants obtained from Coriolis 1; constants can be correlated with those values of the angle ξ for which the bending force constant exhibits a minimum.