First-Principles Study of H2O Adsorption on Oxygen-Covered Fe Surface

2012 ◽  
Vol 706-709 ◽  
pp. 1481-1484 ◽  
Author(s):  
Norio Nunomura ◽  
Satoshi Sunada
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Water Molecules ◽  
First Principle ◽  
Surface Oxygen ◽  
Functional Theory ◽  
First Principle Calculations ◽  
Oxygen Coverage ◽  
Adsorption Of Water

We present the results from first principle calculations of H2O adsorption on oxygen-covered Fe (100) surface. The calculations are based on a density-functional theory, surface modeling which uses supercell slab models. As a surface oxygen coverage increases, the surface is not activated, which makes the adsorption of water molecules on Fe surface unfavorable. It has been found that the surface covered oxygen exerts an influence on the adsorption of H2O molecule on Fe surface.

Density Functional Theory Based Modeling of the Corrosion on Iron Surfaces

2013 ◽  
Vol 58 (2) ◽  
pp. 321-323 ◽  
Author(s):  
N. Nunomura ◽  
S. Sunada
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Atomic Orbital ◽  
Atomic Layer ◽  
Iron Surface ◽  
Basis Set ◽  
Water Molecules ◽  
Aqueous Corrosion ◽  
Functional Theory ◽  
Adsorption Of Water

In order to understand the first steps of the aqueous corrosion of iron, we have performed density functional theory (DFT) based calculations for water molecules and pre-covered oxygen on iron surface. The surface structure is modeled by iron atomic layer and vacuum region, and then oxygen atom and water molecules are displaced on the surface. Self consistent DFT calculations were performed using a numerical atomic orbital basis set and a norm-conserve pseudopotential method. According to our calculations, with increasing surface oxygen coverage, the iron surface is found to be not activated, which leads to a feeble adsorption of water molecules on iron surface. Our results show that the surface covered oxygen exerts an influence on the adsorption of water molecules on iron surface.

Electronic Structures of Vacancy Defective Chiral (6,2) SiC Nanotubes

2017 ◽  
Vol 896 ◽  
pp. 3-8
Author(s):  
Ke Jian Li ◽  
Hong Xia Liu
Keyword(s):  
Density Functional Theory ◽  
Silicon Carbide ◽  
Electronic Structures ◽  
Density Functional ◽  
First Principle ◽  
Defect Level ◽  
Functional Theory ◽  
Vacancy Defects ◽  
First Principle Calculations ◽  
Silicon Carbide Nanotubes

Vacancy defects are common defects formed in the syntheses of silicon carbide nanotubes (SiCNTs) and seriously impact the electronic structures of the nanotubes. With first-principle calculations based on density functional theory (DFT), vacancy defective (6,2) SiCNTs are studied. Vacancies form a pair of fivefold and ninefold rings. Carbon vacancy introduces an occupied defect level near the top of the valence band and an unoccupied level in the conduction band. Three defect levels are found in the band gap of the SiCNT with a silicon vacancy. These results are helpful for investigations on SiCNT devices and sensors.

The Effect of Molecular Orientation and Temperature on the Flow Dynamics of Water Molecules Through a Carbon Nanotube

2007 ◽  
Author(s):  
James Cannon ◽  
Natalie Moore ◽  
Ortwin Hess
Keyword(s):  
Carbon Nanotubes ◽  
Density Functional Theory ◽  
First Principles ◽  
Molecular Orientation ◽  
Density Functional ◽  
Flow Dynamics ◽  
Water Molecules ◽  
Low Density ◽  
Functional Theory ◽  
Different Temperatures

Temperature plays a significant role in determining the dynamics of flow on the nanoscale. This is particularly important with carbon nanotubes, which are likely to form an integral part of future nanofluidic and biological devices. We demonstrate through first-principles density-functional theory (DFT) that the energies and temperatures at which individual water molecules are able to enter the nanotube depends very strongly on their orientation. This has a number of implications for the flow of water through the nanotube at different temperatures and densities, particularly when considering low-density water vapour.

First-Principle Investigation of Lithium Intercalation Behavior of a (3, 3) Carbon Nanotube

2012 ◽  
Vol 736 ◽  
pp. 27-31
Author(s):  
Kulpreet Singh Virdi ◽  
K.C. Hari Kumar
Keyword(s):  
Density Functional Theory ◽  
Carbon Nanotube ◽  
Density Functional ◽  
Lithium Atom ◽  
Energy Difference ◽  
Lithium Intercalation ◽  
First Principle ◽  
Tube Axis ◽  
Functional Theory ◽  
First Principle Calculations

Using first-principle calculations employing density functional theory (DFT) the stabilityof a (3, 3) carbon nanotube (CNT) intercalated with lithium atoms, with respect to their position aswell as Li/C ratio, is studied. On varying the distance of a lithium atom from the axis of the CNT in theradial direction, through the center of a graphitic hexagon, minimum of energy of the system occursat a distance of 3.8 °A from the axis. Keeping the distance of the lithium atom from the tube axis fixedat 3.8 °A, intercalation energy (E) was calculated while the number of lithium atoms is varied fromone (Li1C12, −0.511 eV) to six (Li6C12, −0.615 eV). It is found that the intercalation becomes morefavorable with the increase in number of lithium atoms intercalated and increase in the symmetryof the intercalated system. The maximum intercalation energy difference between successive lithiumatom additions lay within 0.1 eV.

scholarly journals Strain-induced band modulation and excellent stability, transport and optical properties of penta-MP2 (M = Ni, Pd, and Pt) monolayers

2020 ◽  
Vol 2 (10) ◽  
pp. 4566-4580 ◽  
Author(s):  
Vipin Kumar ◽  
Debesh R. Roy
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Electronic Properties ◽  
Density Functional ◽  
First Principle ◽  
Functional Theory ◽  
First Principle Calculations ◽  
Biaxial Tensile ◽  
Tensile Strains ◽  
Excellent Stability

First principle calculations utilizing density functional theory were carried out to investigate electronic properties, transport and optical properties of penta-MP2 (M = Ni, Pd and Pt) monolayer compounds under applied uniaxial and biaxial tensile strains.

scholarly journals In-depth first-principle study on novel MoS2 polymorphs

RSC Advances ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 3759-3769
Author(s):  
Håkon Eidsvåg ◽  
Murugesan Rasukkannu ◽  
Dhayalan Velauthapillai ◽  
Ponniah Vajeeston
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
First Principle ◽  
Functional Theory ◽  
First Principle Calculations ◽  
Photovoltaic Applications

14 new MoS2 polymorphs were studied using first-principle calculations based on density functional theory. We found a new promising MoS2 candidate for photocatalytic and photovoltaic applications.

First-principle calculations of the structure and elastic properties of GaAs under pressure

2009 ◽  
Vol 87 (2) ◽  
pp. 153-159 ◽  
Author(s):  
Hong-Ling Cui ◽  
Fen Luo ◽  
Xiang-Rong Chen ◽  
Guang-Fu Ji
Keyword(s):  
First Principles ◽  
Density Functional ◽  
First Principle ◽  
Pressure Derivative ◽  
Functional Theory ◽  
Plane Wave Method ◽  
First Principle Calculations ◽  
Zinc Blende ◽  
Debye Temperatures ◽  
Theoretical Results

A first-principles plane-wave method with the ultrasoft pseudopotential scheme in the framework of density functional theory is performed to calculate the lattice parameters, the bulk modulus B0 and its pressure derivative B0' of the zinc-blende GaAs (ZB–GaAs), rocksalt GaAs (RS–GaAs), CsCl–GaAs, NiAs–GaAs, and wurtzite GaAs (WZ–GaAs). We also calculate the phase transition pressures between different phases, Debye temperatures, and the anisotropies. Our results are consistent with other theoretical results.

The Influence of Molecular Orientation on the Ability of Water to Enter a Carbon Nanotube at Different Temperatures

2008 ◽  
Author(s):  
James Cannon ◽  
Natalie Moore ◽  
Ortwin Hess
Keyword(s):  
Density Functional Theory ◽  
Significant Role ◽  
First Principles ◽  
Molecular Orientation ◽  
Density Functional ◽  
Water Molecules ◽  
Low Density ◽  
Functional Theory ◽  
Different Temperatures ◽  
The Individual

Temperature plays a significant role in determining the dynamics of flow on the nanoscale. This is particularly important with carbon nanotubes, which are likely to form an integral part of future nanofluidic and biological devices. We demonstrate through first-principles density-functional theory (DFT) that the orientation of the individual water molecules plays a significant role in determining the temperatures and energies at which water is able to enter the nanotube. This has a number of implications for the flow of water through the nanotube at different temperatures and densities, particularly when considering low-density water vapour.

Density functional theory study of Li binding to graphene

RSC Advances ◽  
2016 ◽  
Vol 6 (32) ◽  
pp. 26540-26545 ◽  
Author(s):  
Guangmin Yang ◽  
Xiaofeng Fan ◽  
Zhicong Liang ◽  
Qiang Xu ◽  
Weitao Zheng
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
First Principle ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
First Principle Calculations ◽  
Li Adsorption

Using first-principle calculations, we studied the interaction between Li and graphene by considering the two kinds of models, which are related to the configurations of Li adsorption and the concentration of Li on graphene.

Electronic and magnetic properties of Fe-doped GaN: first-principle calculations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Adam S. Abdalla ◽  
Muhammad Sheraz Khan ◽  
Suliman Alameen ◽  
Mohamed Hassan Eisa ◽  
Osamah Aldaghri
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Density Functional ◽  
Magnetic Semiconductor ◽  
Magnetic Coupling ◽  
First Principle ◽  
Functional Theory ◽  
Electronic And Magnetic Properties ◽  
First Principle Calculations ◽  
Co Doped

Abstract We have systematically studied the effect of Fe co-doped on electronic and magnetic properties of wurtzite gallium nitride (GaN) based on the framework of density functional theory (DFT). It is found that GaN doped with Fe at Ga site is more stable than that at N-site. We calculate the electronic structure of pure and single Fe doped GaN within GGA and GGA + U method and find that Fe doped GaN is a magnetic semiconductor with the total magnetization of 5μ B . The magnetic coupling between Fe spins in Fe-doped GaN is an antiferromagnetic (AFM) under the super-exchange mechanism.

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