【摘要】 使用第一性原理方法研究了锗R8相在压力下的电子结构。计算基于平面波基组,使用模守恒赝势和局域密度近似。对锗R8相结构参数的压力依赖性也进行了研究,包括晶格常数、伞状角、原子位置参数随压力的变化情况。计算得到的R8相的能带结构表明,锗R8相属于半金属相。对总的态密度和分波态密度进行了分析,并考虑了轨道分布情况,态密度呈现出带边的锐化。同时得到锗R8相的两种不同键的键长随压力的变化情况,并分析了这种变化的起因。更多还原

【Abstract】 The electronic structure of Ge R8 phase has been investigated by first-principles method based on plane-wave basis,using norm-conserving pseudopotential and local density approximation.The dependence of structural parameters including lattice constants,rhombohedral angle,and atomic coordinates on pressure was also studied.The computed energy band-structure indicates that Ge R8 phase is a semimetal.Analysis of the total density of states and partial density of states shows a sharpening of valence-band edge,and the distribution of orbits was considered.At the same time,the variation of two different bond lengths was given along pressure which decreases with the increase of pressure;the underlying mechanism is also discussed.更多还原