Ba_8Si_(46)、Ba_8Cu_6Si_(40)和Ba_8Au_6Si_(40)电子特性的研究

A study of electronic properties on Ba_8Si_(46)、Ba_8Cu_6Si_(40) and Ba_8Au_6Si_(40) clathrates

布居分析和态密度结果均表明,Ba8Si46化合物中Ba原子6s轨道上电子一部分向5d轨道转移,另一部分向笼上Si原子3p轨道转移.对于Ba8Cu6Si40、Ba8Au6Si40分析结果表明,由于Cu(Au)向Si转移部分电子,导致了Cu(Au)-6c与Si-24k原子间成键由共价键趋向离子键.带结构的分析表明三者均为弱金属,其中Ba8Cu6Si40和Ba8Au6Si40的导电能力更强一些.

The population and density of states of electrons of the compounds are analyzed in the paper. The results show Ba 6s electrons are transferred in the Ba 5d and Si 3p orbits. For Ba8Au6Si40, Ba8Cu6Si40, Cu （Au） electrons are transferred in the Si. The covalence bond between Cu （Au） and Si atoms tends to electrovalent bond. Band structures of Ba8Si46, Ba8Cu6Si40 and Ba8Au6Si40 are also been analyzed. The results show they are all weak metal, and the conductance of Ba8Cu6Si40 and Ba8Au6Si40 is better than Ba8Si46.