Shape, polarizability, and metallicity in silicon clusters

Journal Article · Tue Mar 01 04:00:00 UTC 2005 · Physical Review. A

DOI:https://doi.org/10.1103/PhysRevA.71.033205· OSTI ID:20650433

Jackson, K A; Yang, M ^[1]; Chaudhuri, I; Frauenheim, Th ^[2]

---

1. Department of Physics, Central Michigan University, Mt. Pleasant, Michigan 48859 (United States)
2. Theoretische Physik, Universitaet Paderborn, D33095 Paderborn (Germany)

We compute the dipole polarizability for Si{sub n} clusters across the prolate to compact shape transition region, n=20-28, and also for a prolate and compact isomer at n=50. We find a clear shape dependence in the calculated values, with prolate structures having systematically larger polarizabilities, and very different trends in per atom polarizabilities with cluster size. The shape dependence is not due to highest unoccupied molecular orbital (HOMO)-lowest unoccupied molecular orbital gap differences or to differences in the binding of the HOMO electron. Instead, charge density analyses show a metalliclike response of the clusters to an external field. In addition, the size trends for the calculated polarizabilities for the compact and prolate clusters are reproduced by the predictions of jellium models for spheres and cylinders, respectively, further suggesting that these small clusters exhibit metallic character.

• OSTI ID: 20650433
• Journal Information: Physical Review. A, Journal Name: Physical Review. A Journal Issue: 3 Vol. 71; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ATOMIC CLUSTERS
ATOMS
CHARGE DENSITY
DIPOLES
ELECTRIC FIELDS
ELECTRONS
ISOMERS
METALS
POLARIZABILITY
SHAPE
SILICON