Using the base "Augmented Spherical Waves (ASW)" the quantities are calculated and discuss "Orbital Crystal Overlap Population (COOP)" and "Orbital Crystal Hamiltonian Population (COHP)" that give information about the formation of states bonding and antibond1ng and consequently on the stability in the system YBa2Cu3O7. The calculation realizes in the reg1on of the crystalline cell that it shows superconductivity. There is demonstrated that in the region is highly unstable in the state not superconductor with a great quantity of states antibonding lor below and in the energy of Fermi E(F). This situation can induce a transit1on of local phase to the state superconductor.

Using the base “Augmented Spherical Waves (ASW)” calculates and discusses the amounts “Crystal Orbital Overlap Population (COOP)” and “Crystal Orbital Hamiltonian Population (COHP)” of Silicon; that they give to information on the formation of bonding and antibonding states, and therefore on the stability in the system. The calculation is realized on Si with diamond cells and FCC, comparing it then for his later interpretation. The calculation of these structures they indicate us a strong instability of the Si FCC, producing a strong internal stress. This instability is due to the great quantity of antibonding states in the all crystal.

Using the base "Augmented Spherical Waves (ASW)" the quantities are calculated and discuss "Orbital Crystal Overlap Population (COOP)" and "Orbital Crystal Hamiltonian Population (COHP)" that give information about the formation of states bonding and antibond1ng and consequently on the stability in the system YBa2Cu3O7. The calculation realizes in the reg1on of the crystalline cell that it shows superconductivity. There is demonstrated that in the region is highly unstable in the state not superconductor with a great quantity of states antibonding lor below and in the energy of Fermi E(F). This situation can induce a transit1on of local phase to the state superconductor.

With ab-initio calculation carried out the analysis of the electronic properties of the topaz in its fundamental state, with different concentrations of Fluorina (F^(-)) and Hidroxilo (OH^(-)) ions, using the package TB-LMTO-ASA. This compound presents optic properties in its natural form with different concentrations of [F^(-),OH^(-)], as well as to the interaction with ionizing radiation. As a result we will have that as much the total energy as the gap fall in non lineal form to the increase of OH ions, being the topaz with 100% F is but stable that the topaz with OH^(-). Product of this increase takes place a phase transformation, increasing of volume and lowering the energy of Ferrni.

By TB-LMTO-ASA method, calculation of the density of states is performed. charge density and electronic localization function topaz and its elements, with the aim of studying the links of its crystalline structure, that when subsequently irradiated with neutrons in the nucleus epiiérmicos reactor RP-1 O, defects will occur in the crystal lattice, changing its optical response. The results show that the aluminum atoms have higher mobilization probabilicfad, this is due to the weak link of the electron delocalization product

With ab-initio calculation carried out the analysis of the electronic properties of the topaz in its fundamental state, with different concentrations of Fluorina (F^(-)) and Hidroxilo (OH^(-)) ions, using the package TB-LMTO-ASA. This compound presents optic properties in its natural form with different concentrations of [F^(-),OH^(-)], as well as to the interaction with ionizing radiation. As a result we will have that as much the total energy as the gap fall in non lineal form to the increase of OH ions, being the topaz with 100% F is but stable that the topaz with OH^(-). Product of this increase takes place a phase transformation, increasing of volume and lowering the energy of Ferrni.

By TB-LMTO-ASA method, calculation of the density of states is performed. charge density and electronic localization function topaz and its elements, with the aim of studying the links of its crystalline structure, that when subsequently irradiated with neutrons in the nucleus epiiérmicos reactor RP-1 O, defects will occur in the crystal lattice, changing its optical response. The results show that the aluminum atoms have higher mobilization probabilicfad, this is due to the weak link of the electron delocalization product

In this work the calculation was made ab-initio of the structure of bands and DOS of the Topaz with Fluoride (F) and Hydroxide (OH) in the fundamental state, with model TB-LMTO-ASA. The conventional cell of these 2 crystals does not present the same dimensions, due to the ion replacement F by molecules OH. The energy states will be affected by this new structure with OH, doing to vary the behavior of the bands, the DOS and therefore varying the optical properties of the crystal.

It was evaluated by means of the method of calculate TB-LMTO-ASA the loading density, TWO and the structure of bands of the different components from the Topaz, with the objective to study enlaces of its crystalline structure, that to the being radiated later with neutrons in the nucleus of reactor RP-10 is the causes of the damage by the irradiation.

En este trabajo se hace un cálculo ab-initio (o de primeros principios) de la estructura electrónica del topacio usando el método LMTO-ASA (Linear Muffin-Tin Orbitals-Atomic Sphere Approximation). El diagrama de la estructura de bandas permite estudiar la coloración que adquiere el topacio al ser irradiado con neutrones del núcleo del reactor RP-10.