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 \(\gamma = 26.94\) mJ K^–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–Γ–X path of the Brillouin zone leading to a collapse of the electronic Fermi surface pocket centered on the Γ–Z direction predicted by density functional theory.