The First Principle Calculation Of Silicon-based Inclusion Complex

In this paper,the first principles calculation of AxCySi46-y(A=Ba?Pb?Eu)crystals were carried out by using WIEN2k and BoltzTraP software package.The electronic structure properties,thermoelectric transport properties and superconductivity were calculated with two different exchange-correlation potentials during the calculating processes.The main results are shown as follows:(1)The electronic structure and thermoelectric transport properties of ?-type cage compounds Ba8Si46 are investigated by the first-principles calculation.The results show that Ba8Si46 is a kind of metal material.The Seebeck coefficient and power factor increased with the increase of the temperature.The power factor(PF)can reach 0.01?W/(m.K2)at 300 K.(2)Starting from the ?-type cage compound Ba8Si46,C is used to replace the cage atoms Si to obtain respectively the crystal structures of the four cage compounds Ba8C6Si40,Ba8C16Si30,BasC22Si24 and BasC24Si22.The results show that the power factor(PF)of BasC24Si22 can reach 0.2?W/(m.K2)at 600 K.The stability and the superconductivity of the four crystal structures are lower than that of Ba8Si46.(3)Beginning with the ?-type cage compound Ba8Si46,Ba in the cage compound are replaced by Pb and Eu to obtain respectively the crystal structures of the two cage compounds Pb8Si46 and Eu8Si46.The results show that they can be successfully synthesized because they all have a stable crystal structure.Eu8Si46 is a kind of magnetic materials,and it has a high density of states near the Fermi surface.