金团簇二维到三维的结构转变和电子特性的理论研究

基于密度泛函PW91/TZVPP理论级别,研究Aun团簇的平衡结构和电子性质。结构优化显示:在n=3~13范围内,Aun团簇的基态构型均为二维结构,当n=14时,开始从二维结构转变成三维结构。原子平均结合能、二阶能量差分、能级间隙、电子亲和势和垂直电离势分析表明:较大金团簇原子之间的结合力强于较小金团簇;偶数金团簇比奇数金团簇具有较高的稳定性;奇数金团簇的化学活性比偶数金团簇高且在化学反应中容易得电子。

The Theoretical Study of the 2D-to-3D Transition and Electronic Properties for Aun Clusters

The equilibrium structures and electronic properties of Au n clusters have been studied using density functional theory at the PW91/TZVPP level.The structural optimizations show that the ground state Au n clusters possess a planar structure for n =3-13 and a solid structure for n=14.The electronic properties of Au n clusters are analyzed based on the averaged binding energy , second-order energy difference , energy gap , the vertical ionization potential and the electron affinity .It is found that the atomic binding energy of big gold clusters is larger than that of small gold clusters .The even-numbered Au n clusters are more stable than the odd -num-bered ones.The chemical activity of the odd -numbered clusters, which is easy to capture an electron,is higher than the even-num-bered ones.