Generalized Gradient Approximation
Mostrando 13-19 de 19 artigos, teses e dissertações.
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13. Glycine adsorption on silicon (001)
In this work we employ the state of the art pseudopotential method, within a generalized gradient approximation to the density functional theory, to investigate the dissociative adsorption process of glycine on the silicon surface. Our total energy calculations indicate that the chemisorption of the molecule is as follow. The gas phase NH2-C2H2-OOH adsorbs m
Brazilian Journal of Physics. Publicado em: 2006-06
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14. The oxidation mechanism of CdTe (110) surface
Using a first-principles pseudopotential technique within a generalized gradient approximation of the density functional theory, we have investigated the mechanism of adsorption of molecular oxygen on the CdTe(110) surface. The determination of the more favorables structures and their formation through the activation barrier analysis indicates that the forma
Brazilian Journal of Physics. Publicado em: 2006-06
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15. Cálculos de primeiros princípios para BaO.
In this work we present first principles calculations with Density Functional Theory, DFT, using norm-conserving pseudopotentials. Initially, we perform calculations of structural properties for metallic barium, Ba, in the Local Density Approximation, LDA, and Generalized Gradient Approximation, GGA, for the exchange and correlation potential. This study aim
Publicado em: 2005
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16. Efeitos de desordem nas propriedades estruturais e termodinamicas de ligas metalicas
O objetivo desta dissertação foi estudar o efeito da ordem local sobre o volume, a energia livre vibracional e a entropia vibracional da liga N i3Al. Esse estudo foi realizado através de cálculos de dinâmica molecular clássica utilizando o potencial empírico de Cleri-Rosato, e as equações de movimento de Martyna, Klein e Tuckerman associadas ao mét
Publicado em: 2005
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17. CH3CN on Si(001): adsorption geometries and electronic structure
In this work we employ the state of the art pseudopotential method, within a generalized gradient approximation to the density functional theory, to investigate the adsorption process of acetonitrile on the silicon surface. Our first-principles calculations indicate that CH3CN adsorbs via a [2+2] cycloaddition reaction through the Cº
Brazilian Journal of Physics. Publicado em: 2004-06
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18. First-principles materials study for spintronics: MnAs and MnN
We report ab-initio all electrons density- functional calculations for the electronic structure of the compounds MnAs and MnN, in the zinc-blende phase. They are potential materials for use in fabrication of new functional semiconductors taking advantage of the spin degree of freedom. The aim is the establishing of the semiconductor spin electronics (spintro
Brazilian Journal of Physics. Publicado em: 2004-06
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19. A theoretical study of acrylonitrile adsorption on Si(001)
The present work is a comparative study of possible adsorption structures of the conjugated molecule acrylonitrile on Si(001) employing the state of the art pseudopotential method, within a generalized gradient approximation to the density functional theory. In the recent literature it is proposed the interaction of acrylonitrile with Si(001) through a cyclo
Brazilian Journal of Physics. Publicado em: 2004-06