Dimers can often be treated as prolate symmetric tops, with their symmetry axis along the dimer axis. In that case, thermal excitation results in J, MJ ≫ K if the moment of inertia around the dimer axis can be assumed much larger than the moment of inertia along an axis perpendicular to it. Expressions are derived which describe the near saturation behaviour of perpendicular and parallel excitations; for J, MJ ≫ K, simple analytical expressions are obtained.@en

IR predissociation spectra of SiF4 and CF3Br clusters have been studied by attenuating a molecular beam with a line-tunable cw CO2 laser. T.@en