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Updated: Oct 11, 2026

Spatial Separation of Molecular Conformers and Clusters
Published on: January 9, 2014
Unique case of highly polarized collision-induced light scattering: the very far spectral wing by the helium pair
Rachet1, Chrysos, Guillot-Noel
1Laboratoire des Proprietes Optiques des Materiaux et Applications, EP CNRS 130, Universite d'Angers, 2, boulevard Lavoisier, 49045 Angers, Cedex, France.
Abstract:
Contrary to what has been observed thus far collision-induced light scattering (CILS) can be completely polarized. This exceptional behavior characterizes the very far wing of the binary CILS spectrum by gaseous helium. This conclusion is drawn from an experimental study of the depolarization ratio of He (2) in a much extended, previously unexplored, spectral domain. Our analysis shows that this property, unique thus far, is mainly due to an almost perfect cancellation between polarization and exchange pair polarizability contributions to the depolarized spectrum, taking place at internuclear distances shorter than the atomic diameter.
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