Structures, electronic and magnetic properties of transition metal atoms encapsulated in Mg12O12 nanocage

The structures, electronic and magnetic properties of a transition metal (TM) atom encapsulated in a Mg12O12 cage have been investigated by the PBE functional. The results show that majority of TM atoms are encapsulated in the Mg12O12 cage except for Sc, Ti, Zr and Hf atoms. The structural stability of Mg12O12 clusters is higher than that of TM@Mg12O12 clusters by average binding energies. Furthermore, Sc, Co, Zr, Rh, Hf, W and Pt atoms are more suitable for the Mg12O12 cage than their neighbors. All the TM atoms can improve the kinetic activity of Mg12O12 cages. For the subgroup IIIB and IVB atoms, the electrons are transferred from the TM atoms to the Mg12O12 cages, while for the subgroup VB-IIB atoms, the opposite situation appears. The maximum values of spin for a TM atom encapsulated in Mg12O12 cages are occurred at the subgroup number VIB (Cr@Mg12O12, Mo@Mg12O12 and W@Mg12O12), respectively.