A Density Functional Tight Binding Model with an Extended Basis Set and Three-Body Repulsion for Hydrogen under Extreme Thermodynamic Conditions

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.

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A Tight-Binding Model for Optical Properties of Porous Silicon

MRS Proceedings ◽

10.1557/proc-491-365 ◽

1997 ◽

Vol 491 ◽

Author(s):

M. Cruz ◽

M. R. Beltran ◽

C. Wang ◽

J. Tagüeña-Martinez

Keyword(s):

Optical Properties ◽

Porous Silicon ◽

Crystalline Silicon ◽

Tight Binding ◽

Basis Set ◽

Extended Defects ◽

Tight Binding Model ◽

Binding Model ◽

Semi Empirical ◽

Good Agreement

ABSTRACTSemi-empirical tight-binding techniques have been extensively used during the last six decades to study local and extended defects as well as aperiodic systems. In this work we propose a tight-binding model capable of describing optical properties of disordered porous materials in a novel way. Besides discussing the details of this approach, we apply it to study porous silicon (p-Si). For this purpose, we use an sp3s* basis set and supercells, where empty columns are digged in the [001] direction in crystalline silicon (c-Si). The disorder of the pores is considered through a random perturbative potential, which relaxes the wave vector selection rule, resulting in a significant enlargement of the optically active k-zone. The dielectric function and the light absorption spectra are calculated. The results are compared with experimental data showing a good agreement.

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Tunable laser and photocurrents from linear atomic C chains

Modern Physics Letters B ◽

10.1142/s0217984915501080 ◽

2015 ◽

Vol 29 (20) ◽

pp. 1550108

Author(s):

Zheng-Zhe Lin

Keyword(s):

Density Functional ◽

Density Functional Theory Calculation ◽

Tight Binding ◽

Tunable Laser ◽

Laser Pulses ◽

Laser Medium ◽

Tight Binding Model ◽

Binding Model ◽

Short Laser Pulses ◽

Theory Calculation

By a tight-binding model, the interaction between linear atomic C chains (LACCs) and short laser pulses was investigated. LACCs were proposed to be used as a medium of laser whose wavelength can be continuously tuned in a range of 321–785[Formula: see text]nm. This data should be more accurate than the previous result [Europhys. Lett. 97 (2012) 27006] because pure density functional theory calculation always underestimates the band gap. According to the tight-binding model, the lifetime of conduction band (CB) bottom is about 1.9–2.3[Formula: see text]ns. The electrons pumped into the CB will quickly fall to the band bottom in a time of ps due to electron–phonon interactions. The above results indicate that LACCs are suitable for laser medium. By [Formula: see text] dichromatic laser pulses, photocurrents can be generated in LACCs, which can be applied as light-controlled signals.

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

Advances in Physical Chemistry ◽

10.1155/2016/1862959 ◽

2016 ◽

Vol 2016 ◽

pp. 1-4 ◽

Cited By ~ 6

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.

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Development of a Multicenter Density Functional Tight Binding Model for Plutonium Surface Hydriding

Journal of Chemical Theory and Computation ◽

10.1021/acs.jctc.8b00165 ◽

2018 ◽

Vol 14 (5) ◽

pp. 2652-2660 ◽

Cited By ~ 11

Author(s):

Nir Goldman ◽

Bálint Aradi ◽

Rebecca K. Lindsey ◽

Laurence E. Fried

Keyword(s):

Density Functional ◽

Tight Binding ◽

Tight Binding Model ◽

Binding Model

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Tight-binding model in optical waveguides: Design principle and transferability for simulation of complex photonics networks

Physical Review A ◽

10.1103/physreva.104.023501 ◽

2021 ◽

Vol 104 (2) ◽

Author(s):

Yang Chen ◽

Xiaoman Chen ◽

Xifeng Ren ◽

Ming Gong ◽

Guang-can Guo

Keyword(s):

Optical Waveguides ◽

Design Principle ◽

Tight Binding ◽

Tight Binding Model ◽

Binding Model

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

Science Advances ◽

10.1126/sciadv.abd4248 ◽

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.

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