V I Anisimov et al 2009 J. Phys.: Condens. Matter 21 075602 doi:10.1088/0953-8984/21/7/075602
V I Anisimov1, Dm M Korotin1, M A Korotin1, A V Kozhevnikov1,2, J Kuneš3,4, A O Shorikov1, S L Skornyakov1 and S V Streltsov1
Show affiliationsThe 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-Tc iron oxypnictides. The average Coulomb repulsion
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
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
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.
71.45.Gm Exchange, correlation, dielectric and magnetic response functions, plasmons
71.15.Mb Density functional theory, local density approximation, gradient and other corrections
74.70.Dd Ternary, quaternary and multinary compounds (including Chevrel phases, borocarbides, etc.)
Issue 7 (18 February 2009)
Received 15 October 2008, in final form 3 December 2008
Published 20 January 2009
V I Anisimov et al 2009 J. Phys.: Condens. Matter 21 075602
Zi-Jian Yao et al 2009 New J. Phys. 11 025009
S Graser et al 2009 New J. Phys. 11 025016
Vladimir I Anisimov et al 1997 J. Phys.: Condens. Matter 9 767
Haozhe Liu et al 2006 J. Phys.: Condens. Matter 18
Rhodri Armour et al 2007 Bioinspir. Biomim. 2 S65
P Miranović et al 2005 J. Phys.: Condens. Matter 17 7971
Paul B. Eskridge et al. 2008 The Astronomical Journal 135 120
M. Haywood 2009 ApJ 698 L1
M Ryle 1950 Rep. Prog. Phys. 13 184