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Electron correlations in a C$_{20}$ fullerene cluster: A lattice density-functional study of the Hubbard model

R. Lopez-Sandoval·G. M. Pastor
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Abstract

The ground-state properties of C$_{20}$ fullerene clusters are determined in the framework of the Hubbard model by using lattice density-functional theory (LDFT) and scaling approximations to the interaction-energy functional. Results are given for the ground-state energy, kinetic and Coulomb energies, local magnetic moments, and charge-excitation gap, as a function of the Coulomb repulsion $U/t$ and for electron or hole doping $δ$ close half-band filling ($|δ| \le 1$). The role of electron correlations is analyzed by comparing the LDFT results with fully unrestricted Hartree-Fock (UHF) calculations which take into account possible noncollinear arrangements of the local spin-polarizations. The consequences of the spin-density-wave symmetry breaking, often found in UHF, and the implications of this study for more complex fullerene structures are discussed.

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R. Lopez-Sandoval, G. M. Pastor. 2005-04-29. Electron correlations in a C$_{20}$ fullerene cluster: A lattice density-functional study of the Hubbard model. https://doi.org/10.1140/epjd%2Fe2006-00038-x

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