Electronic structure of LaMnO3 in the ab initio crystal Hartree-Fock approximation

We find that an ab initio electronic structure calculation in the Hartree-F ock approximation (HFA) leads to the experimentally observed magnetic and o rbital orderings in LaMnO3, as well as its insulating character. While such agreement was also found in density-functional theories (DFT's), there are large differences in other physical predictions. The HFA results are discu ssed vis a vis two different DFT's and an embedded cluster theory, as well as x-ray photoemission and inelastic neutron scattering experiments.