LDA+DMFT computation of the electronic spectrum of NiO

The electronic spectrum, energy gap and local magnetic moment of paramagnetic NiO are computed using the local density approximation plus dynamical mean-field theory LDA DMFT . To this end the noninteracting Hamiltonian obtained within the LDA is expressed in Wannier function basis, with only the five antibonding bands with mainly Ni 3d character taken into account. Complementing it by local Coulomb interactions one arrives at a material-specific many-body Hamiltonian which is solved by DMFT together with quantum Monte Carlo QMC simulations. The large insulating gap in NiO is found to be a result of the strong electronic correlations in the paramagnetic state. In the vicinity of the gap region, the shape of the electronic spectrum calculated in this way is in good agreement with the experimental x-ray-photoemission and bremsstrahlung-isochromat-spectroscopy results of Sawatzky and Allen. The value of the local magnetic moment computed in the paramagnetic phase PM agrees well with that measured in the antiferromagnetic AFM phase. Our results for the electronic spectrum and the local magnetic moment in the PM phase are in accordance with the experimental finding that AFM long-range order has no significant influence on the electronic structure of NiO.