I am trying to make some calculations with FeO. The DFT+U method is used in the literature to correct for the localized Fe d-electrons. Therefore, Same thing was done within ABINIT by adding a Hubbard potential U to the Fe d electrons. I am using the official recommended pseudopotentials table (the PAW JTH table: Fe.GGA_PBE-JTH.xml and O.GGA_PBE-JTH.xml).
FeO was computed in antiferromagnetic AFII structure, in which the magnetic moments are ferromagnetically coupled in the (111) planes and the (111) planes are antiferromagnetically coupled to each other.
I changed U_eff from 0.0 eV to 7.0 eV. I found the FeO is metallic whatever the U was used. The DOS figures are given in below when the U equals 0.0 eV and 4.0 eV. Although a gap can be found when the U equals 4.0 eV, this gap locates below the Fermi energy level. The input file can be found in the attachments.
In addition, I think this mistake maybe contribute to the spin-orbit coupling because I didn't consider the spin-orbit coupling in DFT+U calculations. Actually, when I try to consider spin-orbit coupling in DFT+U, I got such information from
Code: Select all
LDA+U+SpinOrbit is still on test
(not yet in production)
Has anyone else ever encountered such an issue? Any comments would be most appreciated.