Structure and stability of copper clusters: A tight-binding molecular dynamics study
UNSPECIFIED. (2004) Structure and stability of copper clusters: A tight-binding molecular dynamics study. PHYSICAL REVIEW A, 69 (4). -. ISSN 1050-2947Full text not available from this repository.
Official URL: http://dx.doi.org/10.1103/PhysRevA.69.043203
In this paper we propose a tight-binding molecular dynamics with parameters fitted to first-principles calculations on the smaller clusters and with an environment correction, to be a powerful technique for studying large transition-metal/noble-metal clusters. In particular, the structure and stability of Cu-n clusters for n=3-55 are studied by using this technique. The results for small Cu-n clusters (n=3-9) show good agreement with ab initio calculations and available experimental results. In the size range 10less than or equal tonless than or equal to55 most of the clusters adopt icosahedral structure which can be derived from the 13-atom icosahedron, the polyicosahedral 19-, 23-, and 26-atom clusters, and the 55-atom icosahedron, by adding or removing atoms. However, a local geometrical change from icosahedral to decahedral structure is observed for n=40-44 and return to the icosahedral growth pattern is found at n=45 which continues. Electronic "magic numbers" ( n=2, 8, 20, 34, 40) in this regime are correctly reproduced. Due to electron pairing in highest occupied molecular orbitals (HOMOs), even-odd alternation is found. A sudden loss of even-odd alternation in second difference of cluster binding energy, HOMO-LUMO (LUMO, lowest unoccupied molecular orbital) gap energy and ionization potential is observed in the region nsimilar to40 due to structural change there. Interplay between electronic and geometrical structure is found.
|Item Type:||Journal Article|
|Subjects:||Q Science > QC Physics|
|Journal or Publication Title:||PHYSICAL REVIEW A|
|Publisher:||AMERICAN PHYSICAL SOC|
|Official Date:||April 2004|
|Number of Pages:||10|
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