Antiradical capacity of a series of organotin(IV) compounds: A chemical reactivity study in the Density Functional Theory framework

2014 ◽  
Vol 413 ◽  
pp. 143-148 ◽  
Author(s):  
R.A. Delgado-Alfaro ◽  
A.A. Ramos-Organillo ◽  
R. Flores-Moreno ◽  
Z. Gómez-Sandoval
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Reactivity Study ◽  
Theory Framework

scholarly journals New Insights to Understand the CoMFA Analysis within the Density Functional Theory Framework

2021 ◽  
Vol 2 (11) ◽  
pp. 1067-1073
Author(s):  
Roya Momen ◽  
Alejandro Morales-Bayuelo
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Chemical Reactivity ◽  
3D Qsar ◽  
Quantum Similarity ◽  
Functional Theory ◽  
Reactivity Descriptors ◽  
The Density Functional Theory ◽  
Wide Range ◽  
Theory Framework

The Three-Dimensional Quantitative Structure-Activity Relationship (3D QSAR) models now have a wide range of applications; however, new methodologies are required due to the complexity in understanding their results. This research presents a generalized version of quantum similarity field and chemical reactivity descriptors within the density functional theory framework. By taking reference compounds, this generalized methodology can be used to understand the biological activity of a molecular set. In this sense, this methodology allows to study of the CoMFA in quantum similarity and chemical reactivity. It is feasible to investigate steric and electrostatic effects on local substitutions using this method. They were considering that how these methodologies could be used when the receptor is known or unknown.

scholarly journals Polyelectrolyte chain at thermal equilibrium: A comparison between the density functional theory framework (DFT) and the molecular dynamic simulations (MD)

2021 ◽  
Author(s):  
Mike J. Edwards
Keyword(s):  
Density Functional Theory ◽  
Molecular Dynamic ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Molecular Dynamic Simulations ◽  
Dynamic Simulations ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Bjerrum Length ◽  
Theory Framework

ABSTRACTBy means of the density functional theory framework (DFT) as well as the molecular dynamic simulations (MD), a polyelectrolyte chain (PE) in the good solvent conditions at thermal equilibrium is studied. The strength of the electrostatic interactions is varied by the Bjerrum length of the solvent. It turns out that average extension of a PE scales with the degree of polymerization, very much similar to a neutral polymer chain in good solvent. Remarkably, the difference between a PE and a neutral chain appears to be solely in the correlations among monomers which are stored in the Virial coefficients. Interestingly, upon increasing the Bjerrum length of solvent, the chain shrinks. This outcome is confirmed by the DFT framework as well as the MD simulations.SIGNIFICANCEThe significance of this study is that it strongly criticizes the idea (already mentioned in T. Kreer, Soft Matter, 12, 3479 (2016)) that the PEs behave similar to a neutral ideal chain. This study could be useful in our understanding of biopolymers.

scholarly journals Polyelectrolyte brush bilayer under shear at linear and nonlinear response regimes: A combination of the density functional theory framework and the scaling theory

2021 ◽  
Author(s):  
Mike John Edwards
Keyword(s):  
Density Functional Theory ◽  
Shear Rate ◽  
Friction Coefficient ◽  
Electrostatic Interactions ◽  
Density Functional ◽  
Hydrodynamic Interactions ◽  
Functional Theory ◽  
Global Restructuring ◽  
The Density Functional Theory ◽  
Theory Framework

The density functional theory framework and the scaling theory are employed to approach the problem of the Polyelectrolyte brush bilayer under shear. It turns out that, the system at shear rates larger than a critical shear rate undergo a global restructuring during which chains stretch in the shear direction. In the absence of the electrostatic interactions as well as the hydrodynamic interactions, this global restructuring causes a sublinear scaling of the shear stress with the shear rate which makes the shear thinning effect. Nevertheless, in the presence of the hydrodynamic interactions, not only there is no sublinear regime but also a weak superlinear regime which makes a weak shear thickening effect. In the presence of the electrostatic interactions, the stress tensor components change by their second Virial coefficients, however, their shear rate power law are untouched. Nonetheless, the kinetic friction coefficient is independent of the electrostatic interactions. This suggests that the lubrication is not very much different than the neutral bilayers and the electrostatic interactions do not change that. The results of this study offers that maybe nature uses another mechanism to reduce friction coefficient in synovial joint and other biological systems.

scholarly journals Interpenetration between a polymer brush and a polymer star at thermal equilibrium: A theoretical approach

2018 ◽  
Author(s):  
Mike Edwards
Keyword(s):  
Density Functional Theory ◽  
Theoretical Approach ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Polymer Brush ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Theory Framework ◽  
Absorption Transitions ◽  
Standing Problem

By means of the density functional theory framework I tackle the long-standing problem of a polymer star interpenetrating with a polymer brush at thermal equilibrium. Remarkably, the star is repelled to the outside of the brush once it sucks into the brush. It turns out that there could be a highly fluctuating region at the brush edge. The highly fluctuating region would be responsible for discontinuous absorption transitions by brushes. However, up to an small interpenetration length, below which asphericity of the star is maintained, the star gets collapsed by sucking more and more into the brush.

Density-Functional Theory of Atoms and Molecules

1995 ◽  
Author(s):  
Robert G. Parr ◽  
Yang Weitao
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Chemical Potential ◽  
Chemical Reactivity ◽  
Functional Theory ◽  
Atoms And Molecules ◽  
Advanced Students ◽  
The Density Functional Theory ◽  
Background Material ◽  
Structure Of Matter

This book is a rigorous, unified account of the fundamental principles of the density-functional theory of the electronic structure of matter and its applications to atoms and molecules. Containing a detailed discussion of the chemical potential and its derivatives, it provides an understanding of the concepts of electronegativity, hardness and softness, and chemical reactivity. Both the Hohenberg-Kohn-Sham and the Levy-Lieb derivations of the basic theorems are presented, and extensive references to the literature are included. Two introductory chapters and several appendices provide all the background material necessary beyond a knowledge of elementary quantum theory. The book is intended for physicists, chemists, and advanced students in chemistry.

scholarly journals Do Casiopeinas® Prevent Cancer Disease by Acting as Antiradicals? A Chemical Reactivity Study Applying Density Functional Theory

2017 ◽  
Vol 56 (3) ◽  
Author(s):  
Mayra Avelar ◽  
Ana Martínez
Keyword(s):  
Oxidative Stress ◽  
Density Functional Theory ◽  
Free Radicals ◽  
Cancer Cells ◽  
Anticancer Agents ◽  
Density Functional ◽  
Chemical Reactivity ◽  
Cancer Disease ◽  
Functional Theory ◽  
Reactivity Study

The main goal of this investigation is to study the possible mechanisms of Casiopeinas® as anticancer agents. Electrodonating (χ-) and electroaccepting (χ+) electronegativity were calculated applying Density Functional Theory. Two different anticancer mechanisms of Casiopeínas® are proposed. There might be antiradical molecules preventing the formation of cancer cells or these molecules could reduce the amount of GSH and as a result over-produce free radicals, increasing the oxidative stress which in turn kills the cancer cells.

Barium disilicide as a promising thin-film photovoltaic absorber: structural, electronic, and defect properties

2017 ◽  
Vol 5 (48) ◽  
pp. 25293-25302 ◽  
Author(s):  
Mukesh Kumar ◽  
Naoto Umezawa ◽  
Wei Zhou ◽  
Motoharu Imai
Keyword(s):  
Thin Film ◽  
Density Functional Theory ◽  
Solar Cells ◽  
Molecular Orbital ◽  
Density Functional ◽  
Thin Film Solar Cells ◽  
Functional Theory ◽  
Absorber Material ◽  
The Density Functional Theory ◽  
Theory Framework

We report on a barium disilicide (BaSi2) system as a potential absorber material for thin-film solar cells within the density functional theory framework by using advanced methods like GW and BSE and elucidate the first report on the molecular orbital diagram and defect physics in BaSi2.

scholarly journals Metallic and intra-band investigation of optical properties for Borophene nano-sheet: a DFT study

2019 ◽  
Vol 10 (1) ◽  
pp. 33-41
Author(s):  
T. Abasi ◽  
A. Boochani ◽  
S. R. Masharian
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Incident Light ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Semiconductor Behavior ◽  
Structure Density ◽  
Theory Framework

AbstractIn this paper, using the density functional theory framework with the FP-LAPW + lo method by GGA approximation, the electronic and optical properties such as band structure, density of states, dielectric function, energy loss function, absorption and reflection have been investigated for borophene nano-sheet. The optical properties of the borophene have been changed as the incident light direction whereas has the metallic and semiconductor behavior, in the borophene sheet and perpendicular light angles, respectively. Therefore, it can be said that the optical properties of this material are anisotropic.

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