Design of Three-shell Icosahedral Matryoshka Clusters A@B(12)@A(20) (A = Sn, Pb; B = Mg, Zn, Cd, Mn)

We propose a series of icosahedral matryoshka clusters of A@B(12)@A(20) (A = Sn, Pb; B = Mg, Zn, Cd), which possess large HOMO-LUMO gaps (1.29 to 1.54 eV) and low formation energies (0.06 to 0.21 eV/atom). A global minimum search using a genetic algorithm and density functional theory calculations confirms that such onion-like three-shell structures are the ground states for these A(21)B(12) binary clusters. All of these icosahedral matryoshka clusters, including two previously found ones, i.e., [As@Ni(12)@As(20)](3−) and [Sn@Cu(12)@Sn(20)](12−), follow the 108-electron rule, which originates from the high I(h) symmetry and consequently the splitting of superatom orbitals of high angular momentum. More interestingly, two magnetic matryoshka clusters, i.e., Sn@Mn(12)@Sn(20) and Pb@Mn(12)@Pb(20), are designed, which combine a large magnetic moment of 28 µ(B), a moderate HOMO-LUMO gap, and weak inter-cluster interaction energy, making them ideal building blocks in novel magnetic materials and devices.