Multiconfigurational Study of the Electronic Structure of Negatively Charged Fullerens

Multiconfigurational second order perturbation theory was employed in order to describe the ground and excited states of C_60^(-n). Different choices of the active spaces are discussed and the possibility to apply multiconfigurational theory to study C_120 is investigated. The calculations were performed for all possible spin states (for selected charge) and show the preference of low spin state. The energy difference between two C_60^(-3) and pairs C_60^(-1)- C_60^(-5) and C_60^(-2)- C_60^(-4) shows that the probability to create a charge alternation in fullerides is small.