First-principles study of the magic Ar₆Fe⁺ cluster

Complementary to the experimental studies on the magic Ar₆Fe⁺ cluster [Bililign et al., J. Chem. Phys. 108 (1998) 6312], the geometry, magnetic properties, dynamical stability, and magnetic stability are studied in detail by using ab initio molecular orbital calculations. The geometry expected by experimentalists is confirmed. When Ar₆ cluster is doped with Fe⁺, due to the charge transfer, the electronic shells in the Ar atoms are changed from closed to open, resulting in stronger interactions and producing a more compact structure. Because of orbital hybridizations, the Fe atom carries magnetic moment of only 3μ_B.