Dipole moment derivatives and infrared intensities. I. Polar tensors

Abstract

The analysis of infrared intensity data to obtain atomic ``polar tensors,'' introduced first by Biarge, Herranz, and Morcillo (1961), is reviewed and slightly reformulated to make it more consistent with nomenclature currently in use for normal coordinate calculations. Some properties of these polar tensors are examined, including their relation to the ``effective charges'' introduced by King, Mast, and Blanchette (1972). The procedure is illustrated for formaldehyde and for ethylene to obtain the polar tensors and effective charges for the H, C, and O atoms. A revised set of normal coordinates is used for the latter molecule. The results are compared and discussed.