Map of Crystal-Field Effects in Correlated Layered t_{2g}^{n} Perovskites.

Correlated metallic layered t_{2g}^{n} perovskites are intensively studied and yet their low-energy electronic properties remain hotly debated. Important elements of the puzzle, beside the on-site Coulomb repulsion, are the tetragonal crystal-field splitting and the spin-orbit interaction. Here, we show that they control the electronic properties principally via form and occupations of natural orbitals.

Multiorbital Nature of Doped Sr_{2}IrO_{4}.

The low-energy j_{eff}=1/2 band of Sr_{2}IrO_{4} bears stark resemblances with the x^{2}-y^{2} band of La_{2}CuO_{4}, and yet no superconductivity has been found so far by doping Sr_{2}IrO_{4}. Behind such a behavior could be inherent failures of the j_{eff}=1/2 picture, in particular when electrons or holes are introduced in the IrO_{2} planes. In view of this, here we reanalyze the j_{eff}=1/2 scenario.

Fermi Surface of Sr_{2}RuO_{4}: Spin-Orbit and Anisotropic Coulomb Interaction Effects.

The topology of the Fermi surface of Sr_{2}RuO_{4} is well described by local-density approximation calculations with spin-orbit interaction, but the relative size of its different sheets is not. By accounting for many-body effects via dynamical mean-field theory, we show that the standard isotropic Coulomb interaction alone worsens or does not correct this discrepancy. In order to reproduce experiments, it is essential to account for the Coulomb anisotropy.

Electronic structure and magnetism of La4Ni3O8 from first principles.

The magnetic and electronic properties of La(4)Ni(3)O(8) are investigated by performing the full-potential linearized augmented plane wave method. The C-type antiferromagnetic spin ordering is preferred and a molecular correlated insulating state with high-spin Ni ions is found. Our results have proved that this insulating state is caused by a correlation effect and the strong interlayer interaction.