二维全同Nb4团簇在Cu(100)表面的结构稳定性和电子性质

使用基于密度泛函理论的第一性原理赝势法和超原胞模型，研究了吸附在Cu(100)表面上的二维有序排列的幻数团簇Nb₄的结构稳定性及其电子结构性质.计算表明，四面体结构和平面的菱形结构的Nb₄团簇都可以稳定地吸附在Cu(100)表面上，这个体系很可能有重要的应用前景.在Cu(100)表面上，菱形结构的Nb₄比四面体结构的Nb₄更稳定，从Nb₄团簇的四面体结构到菱形结构，需经过的势垒高度约为0.94eV/团蔟.电子结构的计算表明，在Nb₄吸附后，Cu(100)表面与Nb₄团簇间有明显的电荷重新分布，表面Cu原子的电子态密度也明显改变.关键词：4团簇')" href="#">Nb₄团簇有序排列结构稳定性从头计算

Structural stability and electronic properties of ordered identical Nb4 clusters on the Cu(100) surface

First-principles density-functional theory and supercell models are employed to study the structural stability and electronic properties of the periodic two-dimensional arrays of identical Nb₄ clusters on the Cu(100) surface. The total-energy calculations show that Nb₄ clusters with both tetrahedron and quadrangle configurations can be stably absorbed on the Cu(100) surface, which might have important applications. The adsorption of quadrangular Nb₄ clusters is shown to be more stable than that of tetrahedral Nb₄. The energy barrier for the transition of tetrahedral Nb₄ adsorption to the quadrangular one is around 0.94eV/cluster. Electronic structure calculations suggest that adsorption of Nb₄ on Cu(100) surface causes significant charge redistributions between the surface Cu layer and the Nb₄ adsorbate leading to remarkable changes in the electronic structure of the copper surface.