scholarly journals Analysis of a carbon dimer bound to a vacancy in iron using density functional theory and a tight binding model

2013 ◽  
Vol 87 (22) ◽  
Author(s):  
A. T. Paxton ◽  
C. Elsässer
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Tight Binding ◽  
Tight Binding Model ◽  
Binding Model ◽  
Functional Theory

scholarly journals Theoretical Studies of the Stone-Wales Defect in C36 Fullerene Embedded inside Zigzag Carbon Nanotube

2016 ◽  
Vol 2016 ◽  
pp. 1-4 ◽  
Author(s):  
Konstantin S. Grishakov ◽  
Konstantin P. Katin ◽  
Mikhail M. Maslov
Keyword(s):  
Density Functional Theory ◽  
Carbon Nanotube ◽  
Density Functional ◽  
Activation Barrier ◽  
Tight Binding ◽  
Theoretical Studies ◽  
Tight Binding Model ◽  
Binding Model ◽  
Functional Theory ◽  
Wales Defect

We apply density functional theory at PBE/6-311G(d) level as well as nonorthogonal tight-binding model to study the Stone-Wales transformation in C36 fullerene embedded inside the (14,0) zigzag carbon nanotube. We optimize geometries of two different isomers with the D2d and the D6h symmetries and the transition state dividing them. The mechanism of Stone-Wales transformation from D2d to D6h symmetry for the encapsulated C36 is calculated to be the same as for the isolated one. It is found that the outer carbon wall significantly stabilizes the D6h isomer. However, carbon nanotube reduces the activation barrier of Stone-Wales rearrangement by 0.4 eV compared with the corresponding value for the isolated C36.

Composition and Strain Dependence of the Piezoelectric Coefficients in Semiconductor Alloys

2007 ◽  
Vol 1017 ◽  
Author(s):  
T. Hammerschmidt ◽  
M. A. Migliorato ◽  
D. Powell ◽  
A. G. Cullis ◽  
G. P. Srivastava
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Piezoelectric Coefficient ◽  
Tight Binding ◽  
Tight Binding Model ◽  
Semiconductor Alloys ◽  
Binding Model ◽  
Functional Theory ◽  
Photo Current ◽  
Good Agreement

AbstractWe propose a tight-binding model for the polarization that considers direct and dipole contributions and employs microscopic quantities that can be calculated by first-principles methods, e.g. by employing Density Functional Theory (DFT). Applying our model to InxGa1-xAs alloys allows us to settle discrepancies between the values of e14 as obtained from experiments and from linear interpolations between the values of InAs and GaAs. Our calculated piezoelectric coefficient is in very good agreement with photo current measurements of InAs/GaAs(111) quantum well samples.

scholarly journals Single-crystalline epitaxial TiO film: A metal and superconductor, similar to Ti metal

2021 ◽  
Vol 7 (2) ◽  
pp. eabd4248
Author(s):  
Fengmiao Li ◽  
Yuting Zou ◽  
Myung-Geun Han ◽  
Kateryna Foyevtsova ◽  
Hyungki Shin ◽  
...  
Keyword(s):  
Transition Metal ◽  
Density Functional ◽  
Tight Binding ◽  
Crystal Form ◽  
Titanium Monoxide ◽  
Binding Model ◽  
Functional Theory ◽  
Single Crystalline ◽  
First Time ◽  
Lattice Matched

Titanium monoxide (TiO), an important member of the rock salt 3d transition-metal monoxides, has not been studied in the stoichiometric single-crystal form. It has been challenging to prepare stoichiometric TiO due to the highly reactive Ti2+. We adapt a closely lattice-matched MgO(001) substrate and report the successful growth of single-crystalline TiO(001) film using molecular beam epitaxy. This enables a first-time study of stoichiometric TiO thin films, showing that TiO is metal but in proximity to Mott insulating state. We observe a transition to the superconducting phase below 0.5 K close to that of Ti metal. Density functional theory (DFT) and a DFT-based tight-binding model demonstrate the extreme importance of direct Ti–Ti bonding in TiO, suggesting that similar superconductivity exists in TiO and Ti metal. Our work introduces the new concept that TiO behaves more similar to its metal counterpart, distinguishing it from other 3d transition-metal monoxides.

Investigating 3,4-bis(3-nitrofurazan-4-yl)furoxan detonation with a rapidly tuned density functional tight binding model

2021 ◽  
Vol 154 (16) ◽  
pp. 164115
Author(s):  
Rebecca K. Lindsey ◽  
Sorin Bastea ◽  
Nir Goldman ◽  
Laurence E. Fried
Keyword(s):  
Density Functional ◽  
Tight Binding ◽  
Tight Binding Model ◽  
Binding Model

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.

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>

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.

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