Correlation Induced Paramagnetic Ground State in FeAl

摘要: Experimentally the intermetallic compound FeAl is known to be nonmagnetic, whereas conventional density functional theory calculations within local approximation always yield a ferromagnetic ground state with magnetic moment at Fe site of about 0.7 mu(B). We show that correlation correction LDA+U scheme yields nonmagnetic for U>or=3.7 eV using two different implementations. The disappearance occurs since Fe-t(2g) and Fe-e(g) manifolds are affected differently by common U. For large values U solution reappears as expected strong correlation.