钒团簇的几何和电子结构——从分子到体相性质的演化

GEOMETRICAL AND ELECTRONIC STRUCTURES OF VANADIUM CLUSTERS, AND THEIR EVOLUTION FROM MOLECULAR TO BULK PHASE 

基于密度泛函理论 ,优化了钒团簇Vn(n =2— 9,13 ,15 ,19,2 7,5 1)的几何结构 ,通过研究键长、配位数、平均结合能、电离势、电子亲和能、总的态密度和平均磁矩随着尺寸的变化规律 ,从理论上揭示了n≤ 9的钒团簇电子结构具有分立特征的分子行为和很强的尺寸效应 ,13≤n≤ 19是从分子向体相态结构变化的过渡区域 ;V2 7和V51 的态密度已趋向于体相的三峰结构 。

We have optimized the geometrical structures of the vanadium clusters V-n and discussed their evolution with cluster sizes in the average nearest-neighbor distances, coordination numbers, binding energies, ionization potential, electron affinities, density of states, valence band width, and magnetic moments using the density functional theory. We found that the clusters from V-2 to V-9 have distinctly molecular behaviour with dramatic size variations; V-13, V-15, and V-19 are the transition regions from the molecular features to the bulk structures, and V-27 and V-51 possess almost the bulk properties.