三方硒电子结构的EH研究

计算了三螺旋硒链的一维能带, 三方硒的三维能带和Se_6簇的能级。能带分为三组: Se-Se成键带, 孤对电子带和Se-Se反键带。符合Se-Se, 成键的价电子层结构。同时对电子态进行了空间群的对称性分类。为了更广泛的将固体的计算结果与原子簇做比较, 定义了簇轨道重叠布居, 它是原子簇计算态密度的轨道重叠布居权重值。计算表明, Se_6簇(D_(3d))的态密度和簇轨道重叠布居分别与三方硒的态密度和晶体轨道重叠布居颇为类似, 说明两者成键本质的类似性。带隙和态密度与相应的实验数据作了比较。

AN EXTENDED HUCKEL STUDY ON THE ELECTRONIC STRUCTURE OF TRIGONAL SELENIUM

Tightly binding calculations have been performed on the linear screw chain as well as the three dimensional lattice of trigonal selenium. Energy bands can be classified into three sets, namely bonding, nonbonding (lone pair bands) and anti- bonding which have been analyzed in terms of space symmetry. In order to eluci- date the bonding analogy inherent in both the lattice and its finite fragment, a hy- pothetical ring cluster with formula Se_6 is elected and investigated by means of EH program in addition. Parallel to COOP introduced by Hughbanks and Hoffmann, a similar quantity-clusterorbital orverlap population is defined which qualitatively estimates the bonding extent between a pair of atoms distributed in the neighborhood of a fixed energy value. Much like results as drawing in curves of energy bands, density of states and COOP have been shown between the lattice and the hypothetical cluster. This reveals to believe that quite similar electron behaviors exist in this kind of solid and the appropriate finite molecule.