Spin and charge ordering in self-doped Mott insulators

We have investigated possible spin and charge ordered states in (Formula presented) transition-metal oxides with small or negative charge-transfer energy, which can be regarded as self-doped Mott insulators, using Hartree-Fock calculations on (Formula presented)-type lattice models. It was found that an antiferromagnetic state with charge ordering in oxygen (Formula presented) orbitals is favored for relatively large charge-transfer energy and may be relevant for (Formula presented) and (Formula presented) On the other hand, an antiferromagnetic state with charge ordering in transition-metal (Formula presented) orbitals tends to be stable for highly negative charge-transfer energy and can be stabilized by the breathing-type lattice distortion; this is probably realized in (Formula presented).