Geometry and electronic structure of magic iron oxide clusters

The magic iron oxide cluster Fe₁₃O₈ is found by using a reactive laser vaporized cluster source. From first-principles calculations, the equilibrium geometry is determined to be of D₄ₕ symmetry. Comparing with Fe₁₃O₆, Fe₁₂O₉, and Fe₁₄O₇, Fe₁₃O₈ has a closed electron configuration in highest occupied molecular orbital (HOMO), a large gap of HOMO-lowest unoccupied molecular orbital, and large binding energy, which suggest that it is most stable, confirming our experimental observation. The main interaction between oxygen and iron atoms in the cluster is the hybridization between O-2p and Fe-3d orbitals. The electronic structure and magnetic properties for this magic iron oxide cluster are discussed in detail.