Findings of novel metal (M) encapsulated caged clusters of silicon, M@Sin are reported. Depending upon the size of the M atom, silicon forms fullerenelike M@Si16, M = Hf, Zr and cubic M@Si14, M = Fe, Ru, and Os caged clusters. The embedding energy of the M atom is large (~12 eV) due to strong M-Si interactions that make the cage compact. An exceptional result is the large gap of 2.35 eV (in the visible region) for Ti@Si16 and Hf@Si16 in the Frank-Kasper polyhedral structure. Interaction between these clusters is found to be weak, making them attractive for self-assembled cluster materials.The result was published in Physical Review Letters and Nikkei Weekly.
Prof. Kawazoe group（Materials Design by Computer Simulation）