In recent years substantial progress has been achiev the development of accurate ab initio approaches to calculat ing the physical properties of various compounds, and some cases it is now easier to predict the structure of a material theoretically than to make it in a laboratory. 1 For many metals, semiconductors and insulators the local density approximation~LSDA! to the density functiona theory ~DFT! is known to provide a reliable variational de scription of the ground state of the electronic structure of solid. At the same time there are cases where applicat of the DFT-LSDA have been far less successful. In parti lar, difficulties arise when a conventional DFT-LSDA a proach is applied to the treatment of the electronic struc of the material where some of the ions contain partly fill valenced or f shells. It was shown by Terakura et al. that for many of the transition metal oxides the DFT-LSDA pr dicts metallic ground states instead of experimentally served insulating ones. If antiferromagnetic order is tak into account, the DFT-LSDA treatment may lead to an in lating state but the forbidden gap still turns out to be an or of magnitude smaller than that observed using elect spectroscopy. 5 The origin of the failure of the DFT-LSDA in transition metal oxides is known to be associated with inadequate description of the strong Coulomb repulsion tween 3d electrons localized on metal ions. 6 Uranium dioxide represents a similar example of a compound where nium ions contain partly filledf shells and where all of the known LSDA solutions favor metallic conductivity. 7 Experimentally UO2 is known to be a good insulator, 8 and to explain the origin of the insulating ground state, it is necess to go beyond the LSDA. 9 In addition to making incorrec predictions regarding the nature of the ground state of tr
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