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Reliable Estimates of Quasi-Particle Energies and Exci-Tonic Effects in Clusters Through Discrete-Variational-Method Total Energy Calculations

Published online by Cambridge University Press:  10 February 2011

Giancarlo Cappellini
Affiliation:
INFM and Dipartimento di Scienze Fisiche, Università di Cagliari, Italy
Francesco Casula
Affiliation:
INFM and Dipartimento di Scienze Fisiche, Università di Cagliari, Italy
Friedhelm Bechstedt
Affiliation:
FSU, Physikalisch-Astronomische Fakultät, Jena, Germany
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Abstract

Self-energy corrections to the DFT-LDA HOMO-LUMO gap for clusters have been calculated through an efficient method based on ΔSCF theory. Total energies for the clusters are obtained via discrete variational method (DVM). Good results in comparison with experiments and available theoretical data for the sodium tetramer Na4 and C60 have been obtained. The localization properties of DVM basis-functions play a fundamental role in obtaining the above results with a strongly reduced computational effort in comparison with ab-initio schemes. For the two systems under study an estimate of the first excitonic transition energy is also given.

Type
Research Article
Copyright
Copyright © Materials Research Society 1998

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References

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