Theoretical study of metal–insulator transition in rhombohedral vanadium sesquioxide

The electronic structure and the metal–insulator transition (MIT) of V2O3 are investigated in the framework of density functional theory and GGA+U. It is found that, both the insulating and metallic phases can be realized in rhombohedral structure by varying the on-site Coulomb interaction, and the MIT in V2O3 can take place without any structure phase transition. Our calculated energy gap (0.63 eV) agrees with experimental result very well. The metallic phase exhibits high spin (S=1) character, but it becomes S=1/2 in insulating phase. According to our analysis, the Mott–Hubbard and the charge-transfer induce the MIT together, and it supports the mechanism postulated by Tanaka (2002) [11].

► Mott–Hubbard and charge-transfer induce the MIT in V2O3 together.
► Electronic changes across the critical point are demonstrated.
► Theoretical energy gap 0.63 eV agrees with experimental result well.