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arXiv · 0807.0547

Coulomb Parameter U and Correlation Strength in LaFeAsO

V. I. Anisimov·Dm. M. Korotin·S. V. Streltsov·A. V. Kozhevnikov·J. Kuneš·A. O. Shorikov·M. A. Korotin
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Abstract

First principles constrained density functional theory scheme in Wannier functions formalism has been used to calculate Coulomb repulsion U and Hund's exchange J parameters for iron 3d electrons in LaFeAsO. Results strongly depend on the basis set used in calculations: when O-2p, As-4p, and Fe-3d orbitals and corresponding bands are included, computation results in U=3-4 eV, however, with the basis set restricted to Fe-3d orbitals and bands only, computation gives parameters corresponding to F^0=0.8 eV, J=0.5 eV. LDA+DMFT (the Local Density Approximation combined with the Dynamical Mean-Field Theory) calculation with this parameters results in weakly correlated electronic structure that is in agreement with X-ray experimental spectra.

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V. I. Anisimov, Dm. M. Korotin, S. V. Streltsov, A. V. Kozhevnikov, J. Kuneš, A. O. Shorikov, M. A. Korotin. 2008-07-03. Coulomb Parameter U and Correlation Strength in LaFeAsO. https://doi.org/10.1134/s0021364008230069

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