Reconstruction of Nonpolar Gan Surfaces

1996 ◽  
Vol 423 ◽  
Author(s):  
J. Elsner ◽  
M. Haugk ◽  
Th. Frauenheim
Keyword(s):  
Density Functional Theory ◽  
Bond Length ◽  
Density Functional ◽  
Rotation Angle ◽  
Tight Binding ◽  
Functional Theory ◽  
Zinc Blende ◽  
Nonpolar Gan

AbstractA density-functional theory based nonorthogonal tight-binding scheme is used to investigate the nonpolar surfaces of GaN in the wurtzite and zinc-blende phases. In III-V semiconductors the nonpolar surfaces mainly reconstruct by a bond-length conserving rotation of the surface atoms. In contrast to that for all nonpolar GaN surfaces this bond-length is shortened by ≈3 − 4%. We furthermore find the rotation angle to be significantly smaller than could be expected from results for GaAs and GaP.

Diamond {111} Surface: Graphitization or Reconstruction?

1995 ◽  
Vol 383 ◽  
Author(s):  
G. Jungnickel ◽  
D. Porezag ◽  
Th. Frauenheim ◽  
W. R. L. Lambrecht ◽  
B. Segall ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Density Functional Theory ◽  
Density Functional ◽  
Tight Binding ◽  
Diamond Growth ◽  
Functional Theory ◽  
Surface Phases ◽  
Surface Graphitization

ABSTRACTThe reconstruction of the diamond {1111} surface is re-examined by means of density functional theory based tight-binding molecular dynamics. Evidence is found for competition between a graphitizing tendency leading to an unreconstructed but relaxed 1 × 1 surface and a π-bonded chain-like 2 × 1 reconstruction. The implications of the possible co-existence of these two distinct surface phases for diamond growth are discussed.

CH2O Adsorption on M (M = Li, Mg and Al) Atom Deposited ZnO Nano-Cage: DFT Study

2018 ◽  
Vol 786 ◽  
pp. 384-392 ◽  
Author(s):  
Hussein Y. Ammar
Keyword(s):  
Density Functional Theory ◽  
Bond Length ◽  
Density Functional ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structural And Electronic Properties ◽  
Formaldehyde Molecule ◽  
Electronic Configurations ◽  
Adsorption Energies ◽  
Homo Lumo

The structural and electronic properties of Li, Mg and Al deposited ZnO nanocages and their effects on the adsorption of formaldehyde molecule have been investigated using the density functional theory (DFT) computations. To understand the behavior of the adsorbed CH2O molecule on the ZnO nanocage, results of DFT calculations of the M-deposited nanocages (M=Li, Mg and Al), as well as complex systems consisting of the adsorbed CH2O molecule on M-deposited ZnO nanocage were reported. The results presented include adsorption energies, bond lengths, electronic configurations, density of states and molecular orbitals. It was found that, the most energetically stable adsorption configurations of CH2O molecule on the bare ZnO leads to 12% dilation in C=O bond length of CH2O and 14% decrease in HOMO-LUMO gap of ZnO cluster. The most energetically stable adsorption configurations of CH2O molecule on Li, Mg and Al-deposited ZnO lead to 4%, 4% and 11% dilation in C=O bond length of CH2O and-0.66, -45 and , +66% change in HOMO-LUMO gap of ZnO nanocages, respectively. The interaction between CH2O with bare ZnO and M-deposited ZnO nanocages is attributed to charge transfer mechanism. These results may be meaningful for CH2O degradation and detection.

scholarly journals Hydration Dependent Band Gap Tunability of Self-Assembled Phenylalanine-Tryptophan Nanotubes

2020 ◽  
Author(s):  
Hugo Souza ◽  
Antonio Chaves Neto ◽  
Francisco Sousa ◽  
Rodrigo Amorim ◽  
Alexandre Reily Rocha ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Band Gap ◽  
Electronic Properties ◽  
Building Block ◽  
Density Functional ◽  
Tight Binding ◽  
Water Molecules ◽  
Confined Water ◽  
Functional Theory ◽  
Tight Binding Method

In this work, we investigate the effects of building block separation of Phenylalanine-Tryptophan nanotube induced by the confined water molecules on the electronic properties using density-functional theory based tight-binding method. <div><br></div>

Bulk moduli of wurtzite, zinc-blende, and rocksalt phases of ZnO from chemical bond method and density functional theory

2008 ◽  
Vol 92 (10) ◽  
pp. 101917 ◽  
Author(s):  
Changzeng Fan ◽  
Qiang Wang ◽  
Lixiang Li ◽  
Suhong Zhang ◽  
Yan Zhu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Chemical Bond ◽  
Density Functional ◽  
Functional Theory ◽  
Zinc Blende ◽  
Bond Method

scholarly journals Density functional tight binding: values of semi-empirical methods in an ab initio era

2014 ◽  
Vol 16 (28) ◽  
pp. 14368-14377 ◽  
Author(s):  
Qiang Cui ◽  
Marcus Elstner
Keyword(s):  
Density Functional Theory ◽  
Ab Initio ◽  
Density Functional ◽  
Tight Binding ◽  
Empirical Methods ◽  
Functional Theory ◽  
Hartree Fock ◽  
Semi Empirical

Semi-empirical (SE) methods are derived from Hartree–Fock (HF) or Density Functional Theory (DFT) by neglect and approximation of electronic integrals.

Comparative density functional theory–density functional tight binding study of fullerene derivatives: effects due to fullerene size, addends, and crystallinity on band structure, charge transport and optical properties

2017 ◽  
Vol 19 (41) ◽  
pp. 28330-28343 ◽  
Author(s):  
Amrita Pal ◽  
Lai Kai Wen ◽  
Chia Yao Jun ◽  
Il Jeon ◽  
Yutaka Matsuo ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Solid State ◽  
Band Structure ◽  
Charge Transport ◽  
Density Functional ◽  
Tight Binding ◽  
Functional Theory ◽  
Fullerene Derivatives ◽  
Derivatives Of

Comparative DFT–DFTB study of multiple derivatives of C60 and C70 with different addends, in molecular and solid state.

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