(1) Triatomic and larger molecules have more complex energy-level diagrams.

(2) The fluorescence emission spectra of five typical triatomic rare gas halide excimers have been observed from electron-beam-excited high-pressure mixtures.

(3) The solution to the boundary value problem for a 2-dim photodissociation model of a linear triatomic molecule was studied.

(4) With the gradual rising of the pressure in the furnace, the radiation intensity and emissivity of triatomic gases increase, but the increasing range deduce.

(5) The rotation vibration spectra can be classified using irreducible representation of group U(5) for the triatomic molecule.

(6) The development of a broadly tunable excimer laser source by exploiting bound-free transitions of electron beam-pumped diatomic and triatomic are gas halides is described.

(7) Expounded in this article is divided into three chapters, which are summarized as follows:1. Epoxide and its derivatives are important triatomic heterocyclic compounds.