Optical emissions of triatomic rare gas halides

We report in this paper the observation of optical emissions from triatomic rare gas halide molecules formed in excited high density rare gas–halogen mixtures. The broad-band continuum emissions are identified as transitions between ionically bonded excited states (Rg+2X−) and repulsive covalent lower states that dissociate to ground state atoms. These emissions become predominant at high rare gas densities.