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.