The Role of Charge States in the Atomic Structure of Cun and Ptn (n = 2鈥?4 atoms) Clusters: A DFT Investigation
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- 作者：Anderson S. Chaves ; Gustavo G. Rondina ; Maur铆cio J. Piotrowski ; Polina Tereshchuk ; Juarez L. F. Da Silva
- 刊名：Journal of Physical Chemistry A
- 出版年：2014
- 出版时间：November 13, 2014
- 年：2014
- 卷：118
- 期：45
- 页码：10813-10821
- 全文大小：577K
- ISSN：1520-5215
文摘
In general, because of the high computational demand, most theoretical studies addressing cationic and anionic clusters assume structural relaxation from the ground state neutral geometries. Such approach has its limits as some clusters could undergo a drastic structural deformation upon gaining or losing one electron. By engaging symmetry-unrestricted density functional calculations with an extensive search among various structures for each size and state of charge, we addressed the investigation of the technologically relevant Cun and Ptn clusters for n = 2鈥?4 atoms in the cationic, neutral, and anionic states to analyze the behavior of the structural, electronic, and energetic properties as a function of size and charge state. Moreover, we considered potentially high-energy isomers allowing foresight comparison with experimental results. Considering fixed cluster sizes, we found that distinct charge states lead to different structural geometries, revealing a clear tendency of decreasing average coordination as the electron density is increased. This behavior prompts significant changes in all considered properties, namely, energy gaps between occupied and unoccupied states, magnetic moment, detachment energy, ionization potential, center of gravity and 鈥渂andwidth鈥?of occupied d-states, stability function, binding energy, electric dipole moment and sd hybridization. Furthermore, we identified a strong correlation between magic Pt clusters with peaks in sd hybridization index, allowing us to conclude that sd hybridization is one of the mechanisms for stabilization for Ptn clusters. Our results form a well-established basis upon which a deeper understanding of the stability and reactivity of metal clusters can be built, as well as the possibility to tune and exploit cluster properties as a function of size and charge.