An approximation method for evaluating centrifugal distortion constants in XY2 bent symmetric nonhydride molecules

An approximation method is preser ted for an easier evaluation of centrifugal distortion constants τ_αβγδ in XY₂ bent symmetric ronhydride molecules, employing the known extremal properties of the intramolecular force constants. The formulas for τ_αβγδ thus obtained involve only atomic masses, geometry and normal vibrational frequencies of the molecule. The centrifugal distortion constants calculated under this approximation compare very well with experimental values obtained from the microwave spectrum.