ELECTRONIC AND ATOMIC-STRUCTURE OF COPPER CLUSTERS

Autor(en): LAMMERS, U
BORSTEL, G
Stichwörter: CU-2; GEOMETRIC STRUCTURE; GOLD; Materials Science; Materials Science, Multidisciplinary; METAL-CLUSTERS; Physics; Physics, Applied; Physics, Condensed Matter; SHELL STRUCTURE; SILVER
Erscheinungsdatum: 1994
Herausgeber: AMERICAN PHYSICAL SOC
Journal: PHYSICAL REVIEW B
Volumen: 49
Ausgabe: 24
Startseite: 17360
Seitenende: 17377
Zusammenfassung: 
The electronic and geometrical structure of Cu microclusters is investigated utilizing a parametrized tight-binding linear-muffin-tin-orbital (TB-LMTO) method in combination with the real-space recursion technique. The parameters of the TB-LMTO Hamiltonian are derived from ab initio self-consistent k-space TB-LMTO calculations for the corresponding cluster material in its bulk phase for varying lattice constants. It is found that Cu clusters exhibit certain similarities to simple-metal clusters with respect to the gross electronic features: The calculated density-of-state (DOS) spectra exhibit exceptionally large gaps for sizes corresponding to the well-known magic numbers of the spherica jellium model. Likewise, this shell structure shows up as pronounced drops at the magic sizes in calculated ionization potentials, in agreement with recently published experimental data. For the geometrical structure of Cu clusters we find high-symmetry arrangements to be Jahn-Teller unstable. The geometry of the magic Cu20 cluster, obtained by means of the simulated annealing strategy, exhibits a high sphericity, but low overall symmetry. The calculated root-mean-square bond-length fluctuation in Cu20 qualitatively matches the results from molecular dynamics simulations for other materials. Due to the dramatically growing computational difficulties with increasing cluster size, for larger clusters with sizes N > 55, only uniformly relaxed fcc structures were examined. For such geometries, the DOS spectra in the range N almost-equal-to 500 are found to be almost fully converged to the corresponding k-space result of solid Cu.
ISSN: 01631829
DOI: 10.1103/PhysRevB.49.17360

Show full item record

Page view(s)

1
Last Week
0
Last month
0
checked on Feb 26, 2024

Google ScholarTM

Check

Altmetric