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55-Atom clusters of silver and gold: Symmetry breaking by relativistic effects

: Häkkinen, H.; Moseler, M.

Postprint urn:nbn:de:0011-n-366345 (424 KByte PDF)
MD5 Fingerprint: 58faedef03ac28d1443bd78f7f7aa6a4
Erstellt am: 9.4.2009

Pastor, G.M.:
Theory of atomic and molecular clusters : Proceedings of the 4th International Conference TAMC-IV; Toulouse, France, 24 - 28 April, 2004
Amsterdam: Elsevier, 2005 (Computational materials science 35.2006,Nr.3)
International Conference on the Theory of Atomic and Molecular Clusters (TAMC) <4, 2004, Toulouse >
Konferenzbeitrag, Zeitschriftenaufsatz, Elektronische Publikation
Fraunhofer IWM ()
electronic and magnetic properties of clusters; spectroscopy and geometrical structure of clusters; electronic structure of nanoscale material; Cluster; nanoparticle; nanotube; nanocrystal; electronic structure; noble metal nanoparticle; relativistic effect

Anionic 55-atom clusters of gold and silver are studied using density functional theory, scalar relativistic ab initio pseudopotentials and self-consistent generalized gradient corrections. An almost perfect icosahedron is found to be the clear ground state of Ag55, and its electronic density of states agrees almost perfectly with recently measured hight-resolution photoelectron spectra, up to the magnitude of the splitting of the highest free-electron shells by the Ih crystal field. A comparison between theory and a recent experiment allows one to assign icosahedral-based structures also for the Ag57 cluster. On the other hand, the Au55 cluster has several close-lying low-symmetry isomers with a washed-out electron shell sturcture. This qualitative difference between silver and gold clusters is related to the strong relativistic bonding effects in gold.