scholarly journals Trapping of multiple hydrogen atoms in a tungsten monovacancy from first principles

2010 ◽  
Vol 82 (18) ◽  
Author(s):  
Kazuhito Ohsawa ◽  
Junya Goto ◽  
Masahiro Yamakami ◽  
Masatake Yamaguchi ◽  
Masatoshi Yagi
Keyword(s):  
First Principles ◽  
Hydrogen Atoms

First-Principles Study of Interaction of Lithium Atoms with (3, 3) Carbon Nanotubes

2014 ◽  
Vol 687-691 ◽  
pp. 4311-4314 ◽  
Author(s):  
Shun Fu Xu ◽  
Ling Min Li
Keyword(s):  
Carbon Nanotubes ◽  
First Principles ◽  
Density Functional ◽  
Vacancy Defect ◽  
Single Wall Carbon Nanotubes ◽  
Generalized Gradient ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Vacancy Defects ◽  
Adsorption Mechanisms

In this paper, we have employed first-principles calculations to investigate the adsorption mechanisms of one lithium atom on the sidewalls of 1/2/3 H-adsorbed indefective/defective (3, 3) single-wall carbon nanotubes (CNTs) which have vacancy defects. Our calculations are performed within density functional theory (DFT) under the generalized gradient approximation (GGA) of Perdew, Burke, and Ernzerhof (PBE).Our results show that the lithium atoms strongly binds to the H-adsorbed (3, 3) nanotube. Lithium atoms can chemically adsorb on (3, 3) nanotube with the vacancy defect (MVD) without any energy barrier. The lithium adsorption will enhance the electrical conductivity of the nanotube. Further more, the structure of the (3, 3) nanotube with the MVD and hydrogen atoms will become more stable after the three kinds of lithium adsorption.

scholarly journals Relationship between the Behavior of Hydrogen and Hydrogen Bubble Nucleation in Vanadium

Materials ◽  
2020 ◽  
Vol 13 (2) ◽  
pp. 322
Author(s):  
Zhengxiong Su ◽  
Sheng Wang ◽  
Chenyang Lu ◽  
Qing Peng
Keyword(s):  
Hydrogen Atom ◽  
First Principles ◽  
Bound States ◽  
Hydrogen Molecule ◽  
Vacancy Cluster ◽  
Bubble Nucleation ◽  
Hydrogen Bubble ◽  
First Principles Calculations ◽  
Hydrogen Atoms ◽  
Macroscopic Deformation

Hydrogen plays a significant role in the microstructure evolution and macroscopic deformation of materials, causing swelling and surface blistering to reduce service life. In the present work, the atomistic mechanisms of hydrogen bubble nucleation in vanadium were studied by first-principles calculations. The interstitial hydrogen atoms cannot form significant bound states with other hydrogen atoms in bulk vanadium, which explains the absence of hydrogen self-clustering from the experiments. To find the possible origin of hydrogen bubble in vanadium, we explored the minimum sizes of a vacancy cluster in vanadium for the formation of hydrogen molecule. We show that a freestanding hydrogen molecule can form and remain relatively stable in the center of a 54-hydrogen atom saturated 27-vacancy cluster.

scholarly journals Rectifying Performance of Heterojunction Based on α-Borophene Nanoribbons with Edge Passivation

2020 ◽  
Vol 15 (1) ◽  
Author(s):  
Guoliang Yu ◽  
Wence Ding ◽  
Xianbo Xiao ◽  
Xiaobo Li ◽  
Guanghui Zhou
Keyword(s):  
Electronic Transport ◽  
First Principles ◽  
First Principles Calculations ◽  
Zigzag Edge ◽  
Hydrogen Atoms ◽  
Rectification Effect ◽  
Structural Details ◽  
Potential Applications ◽  
Matching Degree ◽  
The Right

Abstract We propose a planar model heterojunction based on α-borophene nanoribbons and study its electronic transport properties. We respectively consider three types of heterojunctions. Each type consists of two zigzag-edge α-borophene nanoribbons (Z αBNR), one is metallic with unpassivated or passivated edges by a hydrogen atom (1H-Z αBNR) and the other is semiconducting with the edge passivated by two hydrogen atoms (2H-Z αBNR) or a single nitrogen atom (N-Z αBNR). Using the first-principles calculations combined with the nonequilibrium Green’s function, we observe that the rectifying performance depends strongly on the atomic structural details of a junction. Specifically, the rectification ratio of the junction is almost unchanged when its left metallic ribbon changes from ZBNR to 1H-Z αBNR. However, its ratio increases from 120 to 240 when the right semiconducting one varies from 2H-Z αBNR to N-Z αBNR. This rectification effect can be explained microscopically by the matching degree the electronic bands between two parts of a junction. Our findings imply that the borophene-based heterojunctions may have potential applications in rectification nano-devices.

Possidle Isomers and Electronic Structure of C60H36

1990 ◽  
Vol 206 ◽  
Author(s):  
B. I. Dunlap ◽  
D. W. Brenner ◽  
R. C. Mowrey ◽  
J. W. Mintmire ◽  
D. H. Robertson ◽  
...  
Keyword(s):  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
High Symmetry ◽  
Hydrogen Atoms ◽  
Functional Methods ◽  
Metastable Structure ◽  
Total Energies ◽  
Rice University

ABSTRACTNewly developed empirical hydrocarbon potentials and self-consistent first-principles local density functional methods are used to investigate possible isomers and the electronic structure of C60H36. Within the high symmetry Th structure conjectured by the groups at Rice University there are two inequivalent sets of hydrogen atoms containing twelve and twenty-four atoms respectively. Binding each set either inside or outside of the C60 cage leads to four isomers of C60H36 with inequivalent strain energies. Although we find that placing twelve hydrogens inside the cage can lead to a metastable structure, our calculated total energies suggest that the isomer with all the hydrogens on the outside of the cage is the energetically most stable.

ELECTRONIC AND OPTICAL PROPERTIES OF NITROGEN DOPED SiC NANOCRYSTALS: FIRST PRINCIPLES STUDY

2013 ◽  
Vol 27 (13) ◽  
pp. 1350053 ◽  
Author(s):  
MASOUD BEZI JAVAN
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Nitrogen Atom ◽  
First Principles ◽  
Density Functional ◽  
High Probability ◽  
Atomic Orbital ◽  
Density Functional Calculation ◽  
Hydrogen Atoms ◽  
Nitrogen Doped

A typical nitrogen doped spherical SiC nanocrystal with a diameter of 1.2 nm ( Si 43 C 44 H 76) using linear combination atomic orbital (LCAO) in combination with pseudopotential density functional calculation have been studied. Our selected SiC nanocrystal has been modeled taking all the cubic bulk SiC atoms contained within a sphere of a given radius and terminating the surface dangling bonds with hydrogen atoms. We have examined nine possible situations in which nitrogen has a high probability for replacement in the lattice or placed between atoms in the nanocrystal. We have found that the silicone can substitute with a nitrogen atom in each layer as the constructed nanocrystals remain thermodynamically stable. Also the nitrogen atom can be placed between the free atomic spaces as the more thermodynamically stable position of the nitrogen is between the topmost layers. Also the optical absorption and refractive index energy dispersions of the pure and various stable doped SiC nanocrystals were studied.

scholarly journals Theoretical investigations of hydrogen absorption in the A15 intermetallics Ti3Sb and Ti3Ir

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Gordon J. Miller ◽  
Ranuri S. Dissanayaka Mudiyanselage ◽  
Weiwei Xie
Keyword(s):  
Intermetallic Compounds ◽  
First Principles ◽  
Electronic Structure Calculations ◽  
Hydrogen Atoms ◽  
Metal Metal ◽  
Theoretical Investigations ◽  
Densities Of States ◽  
The Difference ◽  
Structure Calculations ◽  
Hydrogen Insertion

Abstract Ti3Sb and Ti3Ir adopt the A15 (Cr3Si type) structure and are reported to incorporate hydrogen atoms to an extent, respectively, of Ti3SbH∼3 and Ti3IrH3.8. First-principles electronic structure calculations were performed to identify factors contributing to the difference in maximum hydrogen composition for these two intermetallic compounds. Relative energies and changes in energy densities of states and crystal orbital Hamilton populations upon H insertion in the intermetallic compounds were examined. In both compounds, hydrogen atoms are attracted to [Ti4] tetrahedral interstitial sites over any others. The natures of metal-hydrogen and metalloid-hydrogen bonding and the effects of hydrogen insertion on metal-metal and metal-metalloid bonding have an influence on the maximum hydrogen contents for Ti3Sb and Ti3Ir.

First-principles study of the micro-arrangement of hydrogen atoms and electronic properties of LaNi5Hx (x: 0.5–7)

2008 ◽  
Vol 403 (13-16) ◽  
pp. 2372-2382 ◽  
Author(s):  
Chuanyu Zhang ◽  
Tao Gao ◽  
Xinhua Qi ◽  
Yunguang Zhang ◽  
Lijuan Tang ◽  
...  
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Hydrogen Atoms ◽  
First Principles Study

scholarly journals Hydrogenated derivatives of hexacoordinated metallic Cu2Si monolayer

RSC Advances ◽  
2018 ◽  
Vol 8 (70) ◽  
pp. 39976-39982 ◽  
Author(s):  
E. Unsal ◽  
F. Iyikanat ◽  
H. Sahin ◽  
R. T. Senger
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
Surface Functionalization ◽  
First Principles ◽  
Density Functional ◽  
First Principles Calculations ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Derivatives Of

Herein, we carried out first-principles calculations based on density functional theory to investigate the effects of surface functionalization with hydrogen atoms on structural, dynamical and electronic properties of Cu2Si monolayer.

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