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Phys. Rev. B 75, 085411 (2007) [5 pages]

Questioning the existence of a unique ground-state structure for Si clusters

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Waldemar Hellmann1, R. G. Hennig2, Stefan Goedecker1, C. J. Umrigar3, Bernard Delley4, and T. Lenosky5
1Institut für Physik, Universität Basel, CH-4056 Basel, Switzerland
2Department of Materials Science and Engineering, Cornell University, Ithaca, New York 14853, USA
3Cornell Theory Center, Cornell University, Ithaca, New York 14853, USA
4Paul Scherrer Insitut, WHGA/123, CH-5232 Villigen PSI, Switzerland
5Department of Materials Science and Engineering, Ohio State University, Columbus, Ohio 43210, USA

See Also: Erratum

Received 21 November 2006; published 7 February 2007

Density functional and quantum Monte Carlo calculations challenge the existence of a unique ground-state structure for certain Si clusters. For Si clusters with more than a dozen atoms the lowest ten isomers are close in energy and for some clusters entropic effects change the energetic ordering of the configurations. Isotope pure configurations with rotational symmetry and symmetric configurations containing one additional isotope are disfavored by these effects. Comparisons with experiment are thus difficult since a mixture of configurations is to be expected at thermal equilibrium.

© 2007 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevB.75.085411
DOI:
10.1103/PhysRevB.75.085411
PACS:
61.46.Bc, 71.20.Mq, 71.15.Mb, 05.10.Ln

See Also

Erratum: Waldemar Hellmann, R. G. Hennig, Stefan Goedecker, C. J. Umrigar, Bernard Delley, and T. Lenosky, Erratum: Questioning the existence of a unique ground-state structure for Si clusters [Phys. Rev. B 75, 085411 (2007)], Phys. Rev. B 76, 159903 (2007).