Fuerza, dinámica y optimización estructural

http://www.quantum-espresso.org/

Universidad de Tokio

HPC in Asia Posters

Young Asian and Australiasian researchers and graduate students showcase their latest

research results, new projects and innovation to to a wider audience from Europe and the US at ISC’14, as well as to the HPC in Asia Session attendees who consist of top Asian scientists

and researchers.

Índice• Introducción • Motivación• Nuestro trabajo

QE es un conjunto integrado de aplicaciones para el cálculo de la estructura electrónica y modelización de materiales

en la nanoescala.

Esta basado en la teoría del funcional de la densidad, ondas planas y el uso de pseudopotenciales.

El QE es creado por el Centro Nacional de Simulación DEMOCRITOS (Italia) en colaboración con (ICTP, CINECA,

EPF Lausana, Princeton, MIT).

• El QE se deriva de unificar un número de programas usados en investigación (PWscf, Phonon, CP) en torno a un formato común de archivos de entrada y salida.

Aplicaciones QE se compone de numerosas entre las cuales se

encuentran:

• PWneb: Para el cálculo de energías y trayectorias de reacción con la teoría NEB.

• PHonon. Interacción con fotones a través de la teoría de perturbaciones.

• PWcond: Análisis de la conducción balística.

• TDDFPT: Cálculos espectroscópicos a través de la teoría de perturbaciones dependiente del tiempo

Aplicaciones• PWscf: Cálculo autoconsistente DFT de la estructura electrónica,

relajación estructural, dinámica molecular y estados de transición.

• CP/FPMD: Dinámica molecular.

• PP: Utilidades de postprocesamiento: bandas, densidad de estados, imágenes STM, densidad de carga.

• Atomic: Program de generación de pseudopotenciales.

• PWGui: Interfase gráfica.

Detalles

Programas

http://www.quantum-espresso.org/user_guide/user_guide.html

http://www.tcm.phy.cam.ac.uk/~jry20/gipaw/tutorial_io.pdf

CsCl NaCl NiAs

WZZnS

Ab initio study of the electronic properties of Mg1-xBiXO alloys

Patricia Abdel Rahim1 and Jairo Arbey Rodríguez Martínez 2 , 1,2Universidad Nacional de Colombia, Bogotá, Colombia

1 Universidad Antonio Nariño

.

Using the method in first-principles, we have investigated the electronic properties of the compound Mg1-xBixO with varying concentrations of 0%, 25%, 50% and 75% x of bismuth in the phases in sodium chloride (NaCl), cesium chloride (CsCl), zinc-blende (ZnB), wurtzite (WZ) and nickel arsenidine (NiAs) (including spin).

We calculated the band structure and the density of states in the equilibrium volume of the structures for the different phases. The calculations were performed using the first-principles pseudo-potential method in the framework of the spin Density Functional Theory (DFT). The exchange and correlation effects are treated by using the Generalized Gradient Approximation (GGA) as it is implemented in the Perdew - Burke- Ernzerhof- method (PBE) [1]. The calculations were performed using the pwscf code, distributed with the Quantum-ESPRESSO package [3]

Structural parameters of Mg1-xBiXO alloys

Transiciones de fase para esta estructura

Electronic properties of Mg1-xBiXO alloys in the phase NaCl

MgO Mg0.75Bi0.25O Mg0.5Bi0.5O Mg0.25Bi0.75O

Electronic properties of Mg1-xBiXO alloys in the phase NaCl

MgO Mg0.75Bi0.25O

Mg0.5Bi0.5O Mg0.25Bi0.75O

Electronic properties of Mg1-xBiXO alloys in the phase WZ

MgO Mg0.75Bi0.25O Mg0.5Bi0.5O Mg0.25Bi0.75O

Electronic properties of Mg1-xBiXO alloys in the phase WZ

MgO Mg0.75Bi0.25O

Mg0.5Bi0.5O Mg0.25Bi0.75O

Electronic properties of Mg1-xBiXO alloys in the phase ZnS

MgO Mg0.75Bi0.25O

Mg0.5Bi0.5OMg0.25Bi0.75O

Electronic properties of Mg1-xBiXO alloys in the phase ZnS

MgO Mg0.75Bi0.25O Mg0.5Bi0.5O Mg0.25Bi0.75O

Electronic properties of Mg1-xBiXO alloys in the phase CsCl

MgO Mg0.75Bi0.25O

Mg0.5Bi0.5OMg0.25Bi0.75O

Electronic properties of Mg1-xBiXO alloys in the phase CsCl

MgO Mg0.75Bi0.25O Mg0.5Bi0.5O Mg0.25Bi0.75O

Electronic properties of Mg1-xBiXO alloys in the phase NiAs

MgO Mg0.75Bi0.25O

Mg0.5Bi0.5OMg0.25Bi0.75O

Electronic properties of Mg1-xBiXO alloys in the phase NiAs

MgO Mg0.75Bi0.25O Mg0.5Bi0.5O Mg0.25Bi0.75O

Electronic properties of Mg1-xBiXO alloys in the phase H

MgO Mg0.75Bi0.25O

Mg0.5Bi0.5OMg0.25Bi0.75O

Conclusions

Calculations of electronic properties of Mg1-xBixO were carried out by means of DFT using the Wu-Cohen GGA approximation. It was determined that the MgO has an energy gap the ~ 3 eV and other region down the ~ -1 eV formed mainly by the orbital p the O in the three phases studied and the Mg1-x BixO has a behavior metal for ¼, ½ and ¾ x of Bi in the phases the NaCl, CsCl, NaCl, WZ and ZnS.