Abstract
The theoretical treatment of the unimolecular dissociation reactions of diatomic molecules and diatomic metastable ions has been given in this paper. It is assumed in this theory that the spontaneous dissociation of diatomic molecules or diatomic metastable ions is caused by the process in which an atom or an atomic ion penetrates through the potential barrier formed by the bound potential and the repulsive potential. The rate constant of the spontaneous dissociation reactions due to the quantum mechanical tunnel effect has been calculated in accordance with the WKB method. It has been shown that the plural rate constants for the same unimolecular dissociation can be contributed from discrete virtual energy levels of diatomic molecules or diatomic metastable ions. The application of this theory will give a good explanation for the experimental results of the appearance potentials for diatomic metastable ions.
