Structure Study of ZnO:Eu with the Supercell Method

2010 ◽  
Vol 9 ◽  
pp. 25-30 ◽  
Author(s):  
A. Blanca-Romero ◽  
A. Flores-Riveros ◽  
J.F. Rivas-Silva
Keyword(s):  
Density Functional Theory ◽  
Rare Earth ◽  
Solid State ◽  
Density Functional ◽  
Cell Model ◽  
Structure Study ◽  
Functional Theory ◽  
Kondo Resonance ◽  
Super Cell ◽  
The Density Functional Theory

One of the interests on the study of doped materials with rare earths in their bulk or nanoscale size is owing to the enhancement of the intensity of light in their photoluminescence when a lanthanide exists in a receptor material, as ZnO in our case. Until now, one of the most useful theories for calculations of electronic properties in molecular and solid state systems is the Density Functional Theory (DFT), which is not capable to manage well the presence of high localized electrons, as in lanthanide compounds in general and the doped case in particular. We propose to study these materials with super cell model using some correction to the standard calculations. For this goal, we employ the WIEN2k [1] code using the LDA+U approximation to take into account the strong correlation of the f electrons coming from the lanthanide. We emphasise the study of deformation due to the presence of Eu ion in the structure of host material, optimizing the position of neighboring Oxygen atoms. This deformation has been related to Kondo Resonance [2] appearing around the Fermi Energy of the compound, due to hybridization [3] among the f electrons from rare earth and neighboring oxygen levels.

Theoretical analysis of ammoniaborane and alkylammoniaborane at the solid state

2017 ◽  
Author(s):  
Mariano Méndez Chávez
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Theoretical Analysis ◽  
Gas Phase ◽  
Density Functional ◽  
Structural Parameters ◽  
Ammonia Borane ◽  
Functional Theory ◽  
The Density Functional Theory

This work deals with a benchmark for the calculation of the structural parameters of ammonia-borane and alkylammonia-borane at the solid state, using hybrid and GGA functionals in the framework of the Density Functional Theory as well as the use of Grimme's empirical dispersion. A comparison for some dimers of the aforementioned species, calculated at the gas-phase at the level MP2/aug-cc-pVTZ is discussed.

Theoretical analysis of ammoniaborane and alkylammoniaborane at the solid state

2017 ◽  
Author(s):  
Mariano Mendez Chavez
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Theoretical Analysis ◽  
Gas Phase ◽  
Density Functional ◽  
Structural Parameters ◽  
Ammonia Borane ◽  
Functional Theory ◽  
The Density Functional Theory

This work deals with a benchmark for the calculation of the structural parameters of ammonia-borane and alkylammonia-borane at the solid state, using hybrid and GGA functionals in the framework of the Density Functional Theory as well as the use of Grimme's empirical dispersion. A comparison for some dimers of the aforementioned species, calculated at the gas-phase at the level MP2/aug-cc-pVTZ is discussed.

Mechanical properties and variation in SOC going from La to Nd in intermetallic RIn3 and RSn3 (R = La, Ce, Pr, Nd)

RSC Advances ◽  
2015 ◽  
Vol 5 (49) ◽  
pp. 39416-39423 ◽  
Author(s):  
M. Shafiq ◽  
Iftikhar Ahmad ◽  
S. Jalali-Asadabadi
Keyword(s):  
Mechanical Properties ◽  
Density Functional Theory ◽  
Rare Earth ◽  
Density Functional ◽  
Plane Waves ◽  
Orbital Method ◽  
Full Potential ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Theory Framework

The cubic rare-earth intermetallics RIn3 and RSn3 (R = La, Ce, Pr, Nd) have been investigated using the full potential linearized augmented plane waves plus local orbital method in the density functional theory framework.

scholarly journals Polymorphs of Rb3ScF6: X-ray and Neutron Diffraction, Solid-State NMR, and Density Functional Theory Calculations Study

2021 ◽  
Vol 60 (8) ◽  
pp. 6016-6026
Author(s):  
Aydar Rakhmatullin ◽  
Maxim S. Molokeev ◽  
Graham King ◽  
Ilya B. Polovov ◽  
Konstantin V. Maksimtsev ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Neutron Diffraction ◽  
Solid State Nmr ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
X Ray

scholarly journals Electron-phonon interaction in In-induced √7 ×√3 structures on Si(111) from first-principles

2021 ◽  
Author(s):  
I. Yu. Sklyadneva ◽  
Rolf Heid ◽  
Pedro Miguel Echenique ◽  
Evgueni Chulkov
Keyword(s):  
Density Functional Theory ◽  
Double Layer ◽  
First Principles ◽  
Linear Response ◽  
Density Functional ◽  
Single Layer ◽  
Phonon Interaction ◽  
Functional Theory ◽  
Electron Phonon Interaction ◽  
The Density Functional Theory

Electron-phonon interaction in the Si(111)-supported rectangular √(7 ) ×√3 phases of In is investigated within the density-functional theory and linear-response. For both single-layer and double-layer √(7 ) ×√3 structures, it...

scholarly journals Study on the interaction between catechin and cholesterol by the density functional theory

2020 ◽  
Vol 18 (1) ◽  
pp. 357-368
Author(s):  
Kaiwen Zheng ◽  
Kai Guo ◽  
Jing Xu ◽  
Wei Liu ◽  
Junlang Chen ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Charge Transfer ◽  
Density Functional ◽  
Antioxidant Properties ◽  
Micelle Formation ◽  
Aromatic Rings ◽  
Hydrogen Bond Interaction ◽  
Functional Theory ◽  
The Density Functional Theory

AbstractCatechin – a natural polyphenol substance – has excellent antioxidant properties for the treatment of diseases, especially for cholesterol lowering. Catechin can reduce cholesterol content in micelles by forming insoluble precipitation with cholesterol, thereby reducing the absorption of cholesterol in the intestine. In this study, to better understand the molecular mechanism of catechin and cholesterol, we studied the interaction between typical catechins and cholesterol by the density functional theory. Results show that the adsorption energies between the four catechins and cholesterol are obviously stronger than that of cholesterol themselves, indicating that catechin has an advantage in reducing cholesterol micelle formation. Moreover, it is found that the molecular interactions of the complexes are mainly due to charge transfer of the aromatic rings of the catechins as well as the hydrogen bond interactions. Unlike the intuitive understanding of a complex formed by hydrogen bond interaction, which is positively correlated with the number of hydrogen bonds, the most stable complexes (epicatechin–cholesterol or epigallocatechin–cholesterol) have only one but stronger hydrogen bond, due to charge transfer of the aromatic rings of catechins.

A trinuclear chromium(III) chlorocarbyne

2021 ◽  
Author(s):  
Takashi Kurogi ◽  
Keiichi Irifune ◽  
Takahiro Enoki ◽  
Kazuhiko Takai
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Terminal Alkynes ◽  
Functional Theory ◽  
The Density Functional Theory

Reduction of CCl4 by CrCl2 in THF afforded a trinuclear chromium(III) carbyne [CrCl(thf)2)]3(μ3-CCl)(μ-Cl)3. The chlorocarbyne complex reacted with aldehydes to afford chloroallylic alcohols and terminal alkynes. The density functional theory...

scholarly journals Spectroscopic, X-ray Diffraction and Density Functional Theory Study of Intra- and Intermolecular Hydrogen Bonds in Ortho-(4-tolylsulfonamido)benzamides

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 926
Author(s):  
Malose J. Mphahlele ◽  
Eugene E. Onwu ◽  
Marole M. Maluleka
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Hydrogen Bonds ◽  
Density Functional ◽  
Tetrahedral Geometry ◽  
Hindered Rotation ◽  
Hydrogen Bond Acceptor ◽  
Functional Theory ◽  
Vis Spectroscopy ◽  
Hydrogen Bonded

The conformations of the title compounds were determined in solution (NMR and UV-Vis spectroscopy) and in the solid state (FT-IR and XRD), complemented with density functional theory (DFT) in the gas phase. The nonequivalence of the amide protons of these compounds due to the hindered rotation of the C(O)–NH2 single bond resulted in two distinct resonances of different chemical shift values in the aromatic region of their 1H-NMR spectra. Intramolecular hydrogen bonding interactions between the carbonyl oxygen and the sulfonamide hydrogen atom were observed in the solution phase and solid state. XRD confirmed the ability of the amide moiety of this class of compounds to function as a hydrogen bond acceptor to form a six-membered hydrogen bonded ring and a donor simultaneously to form intermolecular hydrogen bonded complexes of the type N–H···O=S. The distorted tetrahedral geometry of the sulfur atom resulted in a deviation of the sulfonamide moiety from co-planarity of the anthranilamide scaffold, and this geometry enabled oxygen atoms to form hydrogen bonds in higher dimensions.

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