Aim of our work is to study through an ab initio theoretical approach the paramagnetic insulting phase of V2O3 compound, in order to understand better the metal-insulator phase transition subdues by V2O3. It has been shown that at DFT level it’s not possible to describe properly the insulating paramagnetic phase because of a poor treatment of the strong electronic correlation for such systems with d- or f- incomplete shell. Moreover the comparison of DFT density of state with the experimental one is not possible until including many body effect such the ones arising from a direct photoemission spectroscopy. Within a traditional ab initio density functional scheme, the Kohn-Sham eigenvalues can’ t be used for an appropriate description of the electronic bands structures, leading in particular for such a system (VO2, V2O3) to an underestimation or even to a closure of the photoemission band gaps. Moreover, from the experimental point of view, it has been shown that adding small amount of Cr into the V2O3 a sharp metal-insulator transition arises as a function of both Cr concentration and pression at room temperature. We decide to perform ab initio calculation by considering Cr-doped V2O3 supercell system in order to point out which role the presence of the dopant plays on the electronic structure during the metal-insulator paramagnetic transition of the V2O3. Moreover, both the insulating and the metallic phase have been investigated by inelastic xray scattering and compared to the experimental outcomes.
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