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arXiv 1303.0918cond-mat.mtrl-sci
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金纳米粒子的电子壳层结构与化学吸附

Electronic shell structure and chemisorption on gold nanoparticles

Ask Hjorth Larsen, Jesper Kleis, Kristian Sommer Thygesen, Jens Nørskov, Karsten Wedel Jacobsen

摘要:

我们利用密度泛函理论研究了金纳米粒子的电子结构和化学性质。不同的结构家庭的集群进行了比较。对于多达60个原子,我们使用基于DFT的模拟退火优化结构。团簇的几何形状被发现扭曲相当大,在费米能级产生大的带隙。对于多达200个原子,我们认为一个简单的EMT潜力和集群的基础上cuboctahedra和二十面体的结构。所有类型的团簇几何形状都表现出凝胶状的电子壳层结构。我们计算了几个原子在立方八面体团簇上的吸附能。吸附能被发现在幻数突然变化。利用Newns-Anderson模型,我们发现幻数对吸附能的影响可以从吸附物诱导态相对于团簇费米能级的位置来理解。

英文摘要:

We use density functional theory (DFT) to investigate the electronic structure and chemical properties of gold nanoparticles. Different structural families of clusters are compared. For up to 60 atoms we optimize structures using DFT-based simulated annealing. Cluster geometries are found to distort considerably, creating large band gaps at the Fermi level. For up to 200 atoms we consider structures generated with a simple EMT potential and clusters based on cuboctahedra and icosahedra. All types of cluster geometry exhibit jellium-like electronic shell structure. We calculate adsorption energies of several atoms on the cuboctahedral clusters. Adsorption energies are found to vary abruptly at magic numbers. Using a Newns-Anderson model we find that the effect of magic numbers on adsorption energy can be understood from the location of adsorbate-induced states with respect to the cluster Fermi level.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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