American Chemical Society, The Journal of Physical Chemistry A, 45(118), p. 10813-10821, 2014
DOI: 10.1021/jp508220h
Full text: Unavailable
In general, due to 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 struc- tural 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 - 14 atoms in the cationic, neutral, and anionic states, in order to analyze the behavior of the structural, electronic and energetic properties as 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 struc- tural 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 "bandwidth" of occupied d-states, stability function, binding energy, electric dipole moment and s - d hybridization. Furthermore, we identified a strong correlation between magic Pt clusters with peaks in s - d hybridization index, allowing us to conclude that s - d hybridization is one of the mechanisms for stabilizationfor 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 function of size and charge.