Ab Initio Calculations Dft
Mostrando 1-12 de 24 artigos, teses e dissertações.
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1. Ab initio LSDA+U Study of Optical Properties of RVO4 (R = Eu, Ho, Lu) Compounds
A first principles investigation at the pressure 7 GPa of the optical properties of RVO4 (R= Eu, Ho, Lu) orthovanadates in the framework of the density functional theory (DFT) using the linearized-augmented plane-wave method is reported in order to predict new optical materials for continuous-wave lasers. The electronic structure of all orthovanadates is stu
Mat. Res.. Publicado em: 22/01/2018
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2. Ab Initio correlated all electron Dirac-Fock calculations for eka-francium fluoride (E119F)
Resultados obtidos por cálculos Dirac-Fock correlacionados de 4 componentes para o fluoreto do elemento E119 (Eka-Frâncio) com base estável e precisa, livre de prolapso variacional, são reportados neste trabalho. No nível CCSD(T), a distância de equilíbrio Re, frequência harmônica ωe e energia de dissociação De são 2,432 Å, 354,97 cm-1 e 116,92
Journal of the Brazilian Chemical Society. Publicado em: 2012-06
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3. Ab Initio calculations of interactions betweeen Cd and nitrogenous bases o DNA / Cálculos ab initio de interações entre Cd e bases nitrogenadas do DNA
As interações hiperfinas são uma ótima ferramenta para estudar um sítio específico e obter informações importantes sobre o sistema. No presente trabalho analisamos de forma teórica as propriedades eletrônicas, estruturais e hiper nas do Cádmio (Cd) ligado às bases nitrogenadas do DNA. A motivação surgiu da colaboração com o grupo do prof. Art
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 11/05/2011
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4. Simulações de sensores de gás nanoscópicos baseados em nanotubos de carbono: estrutura eletrônica e transporte de elétrons / Computational simulations of nanoscopic gas sensors based on carbon nanotubes: electronic structure and electronic transport
Since their discovery by S. Iijima in 1991, carbon nanotubes have been considered as one of the most promising nanostructured materials for the development of new nanoscopic electronic devices. Due to its high surface area to volume ratio, this material stands out as a candidate for possible gas sensoring applications. In this thesis, we have studied, by mea
Publicado em: 2011
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5. Investigação dos mecanismos de reação de H2O, HF e sarin com hidróxidos lamelares por cálculos ab initio
Os hidróxidos lamelares, dentre os quais se incluem os compostos tipo brucita e os hidróxidos duplos lamelares (HDL), apresentam inúmeras aplicações devido às suas propriedades, tais como: alta estabilidade térmica, capacidade de troca iônica, porosidade e elevada área específica, eletroquímicas, fotoquímicas e outras. A capacidade de adsorção
Publicado em: 2011
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6. Gas-phase solvolysis type reactions of SiCl3+ cations
Gas-phase SiCl3+ ions undergo sequential solvolysis type reactions with water, methanol, ammonia, methylamine and propylene. Studies carried out in a Fourier Transform mass spectrometer reveal that these reactions are facile at 10-8 Torr and give rise to substituted chlorosilyl cations. Ab initio and DFT calculations reveal that these reactions proceed by ad
Química Nova. Publicado em: 2010
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7. Aspectos eletrônicos e estruturais do grafeno e derivados:: um estudo teórico-experimental
In this work we study the electronic and structural properties of graphene and graphene based materials by means of experimental and theoretical techniques. By means of ab-initio calculations using the Density Funcional Theory (DFT), we study the effect of pressure on graphene multi-layers. We look for an explanation for experimental results on the charge in
Publicado em: 2010
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8. Espectroscopia de alcalinos em Hélio líquido / Spectroscopy of Alkali in Liquid Helium
Alkali atoms are good probes for the understanding of liquid He properties. As such considerable experimental attention has been devoted to the analysis of the changes of line position and widths of the absorption spectra of alkali atoms in liquid He environment. On the theoretical side, several studies have used simplified models such as bubble and cluster
Publicado em: 2010
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9. Estudo de nanofios metálicos por primeiros principios
In the present work, we investigate electronic and structural properties of nanowires based on noble metals (Au,Ag,Pt,Pd) and mid-series 4d and 5d transition metals (W,Mo,Ta,Nb). We employ an ab initio methodology implemented in the SIESTA package, based in the Kohn-Sham formulation of density functional theory (DFT). The generalized gradient approximation (
Publicado em: 2010
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10. Defeitos em nanofitas de Grafeno zigzag / Defects in zigzag graphene nanofibres
Graphene and graphene nanoribbons have been attracting a lot of interest from the scientific community because of their novel properties. In this work, a systematic research has been done on the stability and energetics of divacancy, vacancy and Stone-Wales defects in graphene and zigzag graphene nanoribbons. With this goal in mind, ab initio density functio
Publicado em: 2008
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11. AdsorÃÃo de Trihalometanos em Nanotubos de Carbono. / Trihalomethanes Adsorption on Carbon Nanotubes.
In this work we study the interaction of thihalomethanes (THM) with single wall carbon nanotubes using first principles calculations based on the Density Functional Theory (DFT), implemented in the SIESTA code which uses pseudopotentials to describe core electrons and localized basis to expand the valence wavefunctions. The adsorption of CHCl3 (the most impo
Publicado em: 2008
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12. Estudo da adsorção de água em compostos tipo-brucita por cálculos ab initio
The anionic clays, also known as layered double hydroxides (LDH) or hydrotalcitelike compounds, constitute a family of materials whose chemical formula can be represented by: [M2+ (1x) Me3+ x(OH)2]x+ . Amx/ m .nH2O. These compounds have hydroxide planes, or layers, which become permanently positively charged by the substitution of divalent cations M2+ by tri
Publicado em: 2008