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Based on the energies and wavefunctions of quantum dot of several geometries, we located these in the sites of a simple cubical lattice and by means of the Tight-Binding method we calculated the supercrystal electronic structure based on quantum dots. We show how the band structure of these supercrystals depends on the parameter of hopping between quantum dots, which is obtained from our artificial molecule calculations. In addition we present a systematic study of electronic properties of quantum dots arrays depending on the effect of the hopping parameter for three different geometries and finally we predict the band gap values for the semiconducting systems. [ABSTRACT FROM AUTHOR]

The most important electronic properties of perovskite SnTiO3 were studied by ab-initio calculations that use DFT with the Generalized Gradient Aproximation (GGA). Taking Muffin-tin's radius of 2.4, 1.8 and 1.75 Bohr for Sn, Ti y O respectively, and considering a simple cubic structure, we found a lattice parameter which is the minimal for cohesion energy of 7.482 Bohr. Looking at the energy band diagram is seen a energy gap of 1.19 eV. The DOS diagram reveals that the contribution of Sn is negligible an energy while O contributes to occupied states. T i have a majoritary contribution for states above fermi level. [ABSTRACT FROM AUTHOR]

The family of the sulvanite compounds are becoming important as possible candidates as p-type transparent conductors with potential applications in solar cells and electrochromic devices. We have investigated by means of first-principle calculations the electronic properties of these materials. The electronic structure shows that these materials are semiconductors with an indirect bandgap. The calculated bandgaps are 1.02, 1.64 and 1.91 eV for Cu3VS4, Cu3NbS4 and Cu3TaS4, respectively. The character of the valance band maximum is dominated by Cu d-states and the character of the conduction band minimum is due to the TM d-states. This bandgap increment is due to the shift of the conduction band minimum to higher energies when we go down in the column V-B of the periodic table. [ABSTRACT FROM AUTHOR]

In this work we report calculations of the cohesive energy in function of volume, within the density functional theory formalism, in order to find the optimum crystallographic parameter of Boron in its simple cubic phase. We found a cohesive energy Eo =-0.389 Ry, a lattice parameter a =1.880 Å and a bulk modulus Bo=2.290 Mbar. These values are in agreement beside 1% with others reported by first-principles methods. Bands structure diagram confirmed that the simple cubic phase of Boron has a conductor behavior. From the density of states, it was concluded that both s and p orbitals contributed to the metallic character of this phase around Fermi level. [ABSTRACT FROM AUTHOR]

We show the variation on band energy structure, density of states, energy gap and lattice constant of diamond carbon phase when pressure is increased from 0 to 240 GPa. The study was made from first principles using the Density Functional Theory within the generalized gradient approximation. In this interval of pressure variation we found that the bands shape is very stable, the indirect semiconductor characteristic is preserved, and in the valence band p orbital contribution is more important around the Fermi level. [ABSTRACT FROM AUTHOR]

The structural and electronic properties of A2FeMoO6 (A=Ba, Ca), are studied by using ab initio band structure methods. The total and partial densities of states are calculated for each spin polarization on the compounds. As a result, the half metallic property was found on both compounds. Besides, the partial densities of states permitted to infer the mechanism of conduction on this compounds family, based on the Sarma's model. [ABSTRACT FROM AUTHOR]

The electronic states were calculated in volume for the semiconductors Silicon (Si) and Germanium (Ge), using the method Tight-Binding (TB), keeping in mind interactions up to first neighbors. The matrix Hamiltonian was built using a base of orbital atomic s, p and the excited states s*. Based in this approach you proceeded to calculate the relationships of dispersion of the energy E against wave number ᵏ̄, for some addresses of high symmetry in the first zone of Brillouin (PBZ). The characters of the bands and the densities of states were determined (DOS) total and partial according to the orbital characters of the different ones used in the base in which the matrix hamiltonan was written. [ABSTRACT FROM AUTHOR]

Electronic states were calculated in volume for both the Silicon (Si) and Germanium (Ge) semiconductors, by using the method Tight-Binding (TB), keeping in mind interactions up to first neighbors. The Hamiltonian matrix was built using a base of orbital atomic s, p as well as the s* excited states. Based on this approach, the relationships of dispersion of the energy E against wave number k⃗, for some addresses of high symmetry in the first zone of Brillouin (PBZ) were calculated. The characters of the bands and the densities of states were determined (DOS) both total and partial according to the orbital characters of the different ones used in the base in which the matrix Hamiltonian was written. [ABSTRACT FROM AUTHOR]

Using first principles calculations by means the Full-Potential Linearized Plane Wave (FP-LAPW) method, the structural and electronic properties of Ga0.5V0.5N in NaCl and wurtzite structures have been investigated. For wurtzite structure relation c/a and internal parameter u were optimized, with these values: equilibrium volume, lattice constant, cohesion energy and bulk modulus were determinated. Wurtzite was the calculated ground-state structure with lattice constant a=5.953 bohr and bulk modulus B=191.9 GPa. An additional local minimum in the NaCl structure with total energy 0.350 eV/(formula unit) higher was found. On the other hand, band structure calculations for equilibrium volume of Ga0.5V0.5N were presented. Material exhibits metallic behaviour because it does not have an energy gap. [ABSTRACT FROM AUTHOR]