Doubly-charged negative ion of C₆₀

An electronic structure of the negative ion C₆₀^2- has been studied. It is found that in the first approximation of the variational method (when a trial wave function of the extra electrons is a product of one-electron functions) the total energy of the system is negative and that the second electron affinity (EA) of the C₆₀ molecule within the utilized model potentials is about 1 eV. The photodetachment cross sections of the C₆₀^2- ion have been calculated as well; they are found to exhibit two different threshold behaviors with their values being of the same order as the photodetachment cross sections of atomic negative ions with the same EA. (paper)