Coulomb correlations and the electronic structure of bulk V2Te2O

The effect of Coulomb correlations on the electronic structure of bulk van der Waals material V2Te2O is studied by the charge self-consistent density functional theory and dynamical mean-field theory method. Our results show a significant correlation-induced renormalization of the spectral functions in the vicinity of the Fermi energy which is not accompanied by a transfer of the spectral weight to Hubbard bands. The computed quasiparticle effective mass enhancement m*/m for the V 3d states varies from 1.31 to 3.32 indicating an orbital-dependent nature of correlation effects and suggests an orbital-selective formation of local moments in the V 3d shell. We demonstrate that taking into account of Coulomb interaction between the V 3d electrons yields the electronic specific heat coefficient γ= 26.94mJK-2 mol-1 in reasonable agreement with the experiment. We show that the strength of Coulomb correlations is sufficient to trigger a band shift along the Z − Г − X path of the Brillouin zone leading to a collapse of the electronic Fermi surface pocket centered on the Г − Z direction predicted by density functional theory.