Density Function Theory
Mostrando 1-12 de 85 artigos, teses e dissertações.
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1. Through-Bond and Through-Space Interactions in [2,2]Cyclophanes
The interpretation of the distortions of the electron distribution in [2,2]cyclophanes (22-CPs) is controversial. Some studies indicate that there is an accumulation of electron density (ρ) outside the cavity of 22-CPs. The nature of through-space (ts) interaction is still under debate. The relative importance of ts and through-bond (tb) is an open question
J. Braz. Chem. Soc.. Publicado em: 2021-07
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2. Theoretical Calculations on the Mechanism of Hydrogenation of Diphenylacetylene over Pdn (n = 1-4) Clusters
Diphenylacetylene (DPA) is a precursor of stilbene and benzil, and reduction of DPA or its derivatives with metallic reagents is both an old and contemporary topic of research. By means of density function theory (DFT) calculations, a detailed investigation of the mechanism of the hydrogenation of DPA over Pd clusters was carried out at the molecular level.
J. Braz. Chem. Soc.. Publicado em: 2020-10
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3. Investigating Hyperbolic Shear Deformation Theory on vibroacoustic behavior of the infinite Functionally Graded thick plate
Abstract This paper applies acoustic analysis of Sound Transmission Loss (STL) through infinite Functionally Graded (FG) thick plate employing Hyperbolic Shear Deformation Theory (HSDT). The procedure for applying a FG plate is followed by considering the material properties are changed continually based on power-law distribution of the materials in terms of
Lat. Am. j. solids struct.. Publicado em: 04/02/2019
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4. Improved Electronic Structure and Optical Performance of Bi2Te3-xSex From First-principle Calculations Within TB-mBJ Exchange Potential
Using the first-principle calculations of density functional theory within the (FP-LAPW) method, we have investigated the structural, electronic and optical properties of Bi2Te3-xSex alloys with compositions x = 0, 1, 2 and 3 of Se. The generalized gradient approximation functional of Wu and Cohen (GGA-PBE) is used to calculate ground state structural parame
Mat. Res.. Publicado em: 17/11/2017
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5. Thermodynamic bounds for existence of normal shock in compressible fluid flow in pipes
Abstract The present paper is concerned with the thermodynamic theory of the normal shock in compressible fluid flow in pipes, in the lights of the pioneering works of Lord Rayleigh and G. Fanno. The theory of normal shock in pipes is currently presented in terms of the Rayleigh and Fanno curves, which are shown to cross each other in two points, one corresp
An. Acad. Bras. Ciênc.. Publicado em: 2017-06
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6. Computational Simulations of Morphological Transformations by Surface Structures: The Case of Rutile TiO2 phase
Computational simulations based on periodic density functional theory have been carried out to investigate the control of crystal morphology by accurate values of surface energies by Wulff theorem. This method can be used as a very useful tool for the design and knowledge of synthesis of new materials. In a special case, rutile TiO2 phase, exhibits great var
Mat. Res.. Publicado em: 10/04/2017
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7. NATURALEZA DE LAS INTERACCIONES Mδ+...δ+C-Oδ- EN CARBONILOS METÁLICOS. UN ESTUDIO BASADO EN LA TOPOLOGÍA DE LA DENSIDAD DE CARGA ELECTRÓNICA Y SU FUNCIÓN LAPLACIANA
The nature of the metal-ligand interactions, in the [Ti(CO)6]2-, [V(CO)6]-, [Cr(CO)6], [Mn(CO)6]+, [Fe(CO)6]2+ and [Co(CO)6]3+ complexes has been studied by means of topological analyses of the electron charge density, using the Quantum Theory of Atoms in Molecules (QTAIM) and Electron Function Localization (ELF). The calculations were made using B3LYP metho
Quím. Nova. Publicado em: 2016-07
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8. CURRENT-VOLTAGE CURVES FOR TREATING EFFLUENT CONTAINING HEDP: DETERMINATION OF THE LIMITING CURRENT
Abstract Membrane separation techniques have been explored for treating industrial effluents to allow water reuse and component recovery. In an electrodialysis system, concentration polarization causes undesirable alterations in the ionic transportation mechanism. The graphic construction of the current voltage curve is proposed for establishing the value of
Braz. J. Chem. Eng.. Publicado em: 2015-12
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9. Electrochemical and Optical Investigation of Conductive Polymer and MWCNT Nanocomposite Film
Composites of multi-walled carbon nanotubes (MWCNT) and conductive polymer with good uniformity were prepared by electropolymerization. Molecular modeling calculations were carried out for electroactive monomer (OAP) polymerization with density functional theory (DFT) level using 6-311G(d,p) basis set for all atoms and Gaussian 03 program package. The reflec
J. Braz. Chem. Soc.. Publicado em: 2015-02
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10. Ab. initio study of the structural, elastic, electronic and optical properties of Cu3N
Electronic, optical, elastic, properties of Copper nitride (Cu3N) in cubic anti- ReO3 phase have been studied using the full-potential augmented plane waves (FP-LAPW) within density functional theory (DFT) framework. Generalized gradient approximation (GGA), local density approximation (LDA), Perdew - Burke - Ernzerhof generalized parameterization of gradien
Mat. Res.. Publicado em: 01/04/2014
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11. Prediction of monomer reactivity in radical copolymerizations from transition state quantum chemical descriptors
In comparison with the Q-e scheme, the Revised Patterns Scheme: the U, V Version (the U-V scheme) has greatly improved both its accessibility and its accuracy in interpreting and predicting the reactivity of a monomer in free-radical copolymerizations. Quantitative structure-activity relationship (QSAR) models were developed to predict the reactivity paramet
Polímeros. Publicado em: 20/08/2013
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12. Produção ultrarrápida de fibras de carbono ativadas a partir de pan têxtil
Através do emprego de fibra de poliacrilonitrila (PAN) têxtil comercial fornecida pela Radici Fibras Ltda, este trabalho apresenta o estudo para a produção de Fibra de Carbono Ativada (ACF, do inglês: Activated Carbon Fiber) microporosa a partir de fibra PAN têxtil nacional. Fibras com 5,0 dtex foram oxidadas termicamente em patamares distintos, produz
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 12/07/2012