Strukturelle und energetische Eigenschaften von bimetallischen Clustern

双金属团簇的结构和能量特性

• 批准号: 35387534
• 负责人: Professor Dr. Michael Springborg
• 金额: --
• 依托单位: Arbeitsgruppe für Physikalische und Theoretische Chemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2007
• 资助国家: 德国
• 起止时间: 2006-12-31 至 2011-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/35387534?language=en
• 关键词: Strukturelle; und; energetische; Eigenschaften; von

A systematic and complete investigation of the structural, energetic, vibrational, and thermodynamic properties of bimetallic clusters AmBn with N = m + n from 2 to 60 will be carried through for each cluster size and each composition. As metals we consider Ni, Cu, Ag, Pt, Pd, and Au, that have different atomic radii as well as bulk and surface properties, in order to understand both generic and material-specific features. The lowest-energy structures are to be determined using a combination of the embeddedatom method to model the interatomic interaction and the basin-hopping algorithm for the unbiased determination of the global total-energy minimum. The most stable stoichiometries shall be identified by using various definitions of stability functions, the excess energy, and the energy difference between the first and second lowest isomers. The obtained lowest-energy structures will be further optimized by more advanced density functional theory methods employing the realistic exchange-correlation potentials determined for each metal pair A–B by using the procedure developed by us. Furthermore, the full vibrational spectrum of the nanoalloys will be calculated. Finally, with help of the harmonic superposition approximation the thermodynamic properties, including heat capacity, Debye temperature, and solidsolid phase transition temperatures, will be calculated for the first time. The derived results including the developed schemes and procedures can be used in different fields of cluster science such as ”Structure and thermodynamics”, ”Electronic structure and quantum (size) effects”, ”Spectroscopy and dynamics”, ”Catalysis”, ”Optical properties and plasmonics”.

一个系统和完整的调查的结构，能量，振动和热力学性质的NH3集群AmBn与N = m + n从2到60将进行通过每个集群的大小和每个组合物。作为金属，我们考虑Ni、Cu、Ag、Pt、Pd和Au，它们具有不同的原子半径以及体和表面性质，以便理解通用和材料特定的特征。最低能量的结构是使用embeddedatom方法来模拟原子间的相互作用和盆跳跃算法的无偏确定的全球总能量最小值的组合来确定。最稳定的化学计量应通过使用稳定性函数的各种定义、过剩能量以及第一和第二最低异构体之间的能量差来确定。得到的最低能量结构将进一步优化更先进的密度泛函理论方法采用现实的交换相关势确定每个金属对A-B通过使用我们开发的程序。此外，将计算纳米合金的全振动光谱。最后，借助于谐波叠加近似，首次计算了该体系的热力学性质，包括热容、德拜温度和固-固相变温度。所得到的结果包括所发展的方案和程序，可以用于团簇科学的不同领域，如“结构和热力学”，“电子结构和量子（尺寸）效应”，“光谱学和动力学”，“催化”，“光学性质和等离子体”。