Anisimov VI, Korotin DM, Korotin MA, Kozhevnikov AV, Kuneš J, Shorikov AO, Skornyakov SL, Streltsov SV. Coulomb repulsion and correlation strength in LaFeAsO from density functional and dynamical mean-field theories.
JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009;
21:075602. [PMID:
21817332 DOI:
10.1088/0953-8984/21/7/075602]
[Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The LDA+DMFT (local density approximation combined with dynamical mean-field theory) computation scheme has been used to calculate spectral properties of LaFeAsO-the parent compound of the new high-T(c) iron oxypnictides. The average Coulomb repulsion [Formula: see text] and Hund's exchange J parameters for iron 3d electrons were calculated using the first-principles constrained density functional theory scheme in the Wannier functions formalism. Resulting values strongly depend on the number of states taken into account in the calculations: when the full set of O-2p, As-4p and Fe-3d orbitals and the corresponding bands are included, the interaction parameters [Formula: see text] eV and J = 0.8 eV are obtained. In contrast, when the basis set is restricted to the Fe-3d orbitals and bands only, the calculation gives much smaller values of [Formula: see text] eV, J = 0.5 eV. Nevertheless, DMFT calculations with both parameter sets and the corresponding basis sets result in a weakly correlated electronic structure that is in agreement with the experimental x-ray and photoemission spectra.
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