Intensities of Pure Rotational Band Systems of Symmetric Top Molecules

摘要

An exact expression for the total intensity of the pure rotational band system of a rigid symmetric top molecule is derived. An approximate expression for the mean spectral absorption coefficient is obtained and is compared with previously published results. The first-order effects of non-rigidity and mechanical anharmonicity on the band intensity are investigated in the special case of a diatomic molecule and found to be small in general. (Author)