The extended Hubbard Hamiltonian on a bcc lattice is studied at half-filling and for a finite hopping between next-nearest-neighbours, in mean-field approximation. An ionic insulating broken-symmetry phase is predicted for any hydrogenoid bcc solid in the density range 1.0 < r s < 2.6. The occurrence of an ionic phase would explain the failure to achieve hydrogen metallization at high pressures...

The problem of importance of strong correlations for the electronic structure, transport, and magnetic properties of half-metallic ferromagnetic CrO2 is addressed by performing density functional electronic structure calculations in the local spin density approximation sLSDAd as well as using the LSDA1U method. It is shown that the corresponding low-temperature experimental data are best fitted...

We present the effective action and self-consistency equations for the bosonic dynamical mean field approximation to the bosonic Hubbard model and show that it provides remarkably accurate phase diagrams and correlation functions. To solve the bosonic dynamical mean field equations, we use a continuous-time Monte Carlo method for bosonic impurity models based on a diagrammatic expansion in the ...

We study the pseudogaps in the spectra of the 2D Hubbard model using both finite-size and dynamical cluster approximation (DCA) quantum Monte Carlo calculations. At half-filling, a charge pseudogap, accompanied by non-Fermi-liquid behavior in the self-energy, is shown to persist in the thermodynamic limit. The DCA (finite-size) method systematically underestimates (overestimates) the width of t...

We perform a detailed study of the phase transitions and mechanisms electron localization in extended Hubbard model using dynamical cluster approximation on $2\times 2$ cluster. explore interplay charge order Mott physics. find that nearest-neighbor Coulomb interaction $V$ causes "screening" effects close to transition, pushing boundary larger values $U$. also demonstrate different correlations...