Knowledge Bank

Microwave measurements of the rare gas dimers have been extended to the trimers $Ne2-Kr$ and $Ne2-Xe$. Rotational spectra of several isotopomers of each complex have been measured with a cavity pulsed microwave Fourier transform spectrometer. Rotational and centrifugal distortion constants have been evaluated, from which the geometries and harmonic force fields of the complexes have been derived. Observation of the spectra of these fundamental trimers makes it possible to compare their properties to those of their constituent rare gas dimers. The three-body additivity and non-additivity of their properties will be discussed.