Elastic interaction of hydrogen atoms on graphene: A multiscale approach from first principles to continuum elasticity

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.

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

Materials ◽

10.3390/ma13020322 ◽

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.

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First-principles calculations for Li adatom diffusion on a graphene surface through a V6 defect partly terminated by hydrogen atoms

Japanese Journal of Applied Physics ◽

10.7567/1347-4065/ab00f2 ◽

2019 ◽

Vol 58 (SB) ◽

pp. SBBH07 ◽

Cited By ~ 1

Author(s):

Takazumi Kawai ◽

Kento Shiota

Keyword(s):

First Principles ◽

First Principles Calculations ◽

Hydrogen Atoms ◽

Graphene Surface ◽

Adatom Diffusion

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

Nanoscale Research Letters ◽

10.1186/s11671-020-03417-7 ◽

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.

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Multiscale modelling for tokamak pedestals

Journal of Plasma Physics ◽

10.1017/s0022377818000326 ◽

2018 ◽

Vol 84 (2) ◽

Cited By ~ 2

Author(s):

I. G. Abel ◽

A. Hallenbert

Keyword(s):

First Principles ◽

Detailed Comparison ◽

Multiscale Approach ◽

Systems Of Equations ◽

Line Region ◽

Open Field Line ◽

Small Parameters ◽

The Relationship ◽

Kinetic Physics ◽

Current Modelling

Pedestal modelling is crucial to predict the performance of future fusion devices. Current modelling efforts suffer either from a lack of kinetic physics, or an excess of computational complexity. To ameliorate these problems, we take a first-principles multiscale approach to the pedestal. We will present three separate sets of equations, covering the dynamics of edge localised modes (ELMs), the inter-ELM pedestal and pedestal turbulence, respectively. Precisely how these equations should be coupled to each other is covered in detail. This framework is completely self-consistent; it is derived from first principles by means of an asymptotic expansion of the fundamental Vlasov–Landau–Maxwell system in appropriate small parameters. The derivation exploits the narrowness of the pedestal region, the smallness of the thermal gyroradius and the low plasma$\unicode[STIX]{x1D6FD}$(the ratio of thermal to magnetic pressures) typical of current pedestal operation to achieve its simplifications. The relationship between this framework and gyrokinetics is analysed, and possibilities to directly match our systems of equations onto multiscale gyrokinetics are explored. A detailed comparison between our model and other models in the literature is performed. Finally, the potential for matching this framework onto an open-field-line region is briefly discussed.

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Possidle Isomers and Electronic Structure of C60H36

MRS Proceedings ◽

10.1557/proc-206-687 ◽

1990 ◽

Vol 206 ◽

Cited By ~ 3

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.

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Modeling Precipitate Microstructure Evolution in Alloys with First-Principles Energetic Information

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.19 ◽

2004 ◽

Vol 449-452 ◽

pp. 19-24 ◽

Cited By ~ 2

Author(s):

Veeramuthu Vaithianathan ◽

C. Wolverton ◽

Long Qing Chen

Keyword(s):

First Principles ◽

Linear Response ◽

Linear Response Theory ◽

Field Method ◽

Phase Field Method ◽

Multiscale Approach ◽

Recent Effort ◽

Short Article ◽

Precipitate Microstructure ◽

Al Matrix

This short article reports our recent effort to integrate the mesoscale phase-field method with first-principles total energy calculations, linear response theory, as well as mixedspace cluster expansion. A particular example of applying such a multiscale approach to the case of precipitation of semicoherent θ' particles in an Al-matrix is presented.

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

International Journal of Modern Physics B ◽

10.1142/s0217979213500537 ◽

2013 ◽

Vol 27 (13) ◽

pp. 1350053 ◽

Cited By ~ 1

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.

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