Ru_n(n=2~8)金属团簇的结构和能级分布的DFT研究

采用密度泛函理论中的广义梯度近似(DFT/GGA)方法,对Run团簇(n = 2~8)的几何结构与稳定性、束缚能以及能级分布的关系进行了研究,并分析了随着团簇原子数的增加,团簇的几何结构和费米能级的变化,结果表明:Ru簇的几何结构在4个原子以前是平面结构,而从5个原子开始为空间立体的稳定结构,束缚能随金属原子数的增加而增加。能级结构呈明显的分立特征,费米能级随原子个数的增加而增加,但从Ru7开始又有所降低,且团簇的能量间隙逐渐减小,趋近于大块金属的能级特征。

DFT Study on the Geometry and Energy Level Distribution of Metal Clusters Run (n = 2～8)

In this paper, the geometry, stability, binding energy and energy level distribution of small clusters of Ru2～8 are investigated by Density Functional Theory (DFT). The changes of geometry and energy level with the increase of cluster sizes are also analyzed. The Ru2～8 clusters with four or less atoms have two- dimensional planar structures, the typical pattern of close packing; while those with five to eight atoms have three-dimensional structures. The binding energies increase as the increasing of the number of atoms. The energy levels are apparently discontinuous in the Ru2～8 clusters. The Fermi level increases with the atoms up to seven and the energy gaps decrease gradually, close to the energy feature of bulk metals.