scholarly journals Structure and Properties of Chained Carbon: Recent Ab Initio Studies

2019 ◽  
Vol 5 (3) ◽  
pp. 56 ◽  
Author(s):  
Buntov ◽  
Zatsepin ◽  
Kitayeva ◽  
Vagapov
Keyword(s):  
Thermal Conduction ◽  
Density Functional ◽  
Theoretical Work ◽  
Static Properties ◽  
Functional Theory ◽  
Carbon Chains ◽  
Current State ◽  
Carbon Structures ◽  
Phonon Spectra ◽  
State Of Research

Carbon chains or carbyne-like structures represent the next generation of 1D materials whose properties can be tuned by the chain length, doping, and the type of termination. Currently inaccessible technology of the macroscopic carbyne synthesis and characterization makes theoretical work especially valuable. The state of the art methods being applied in the field are density functional theory and molecular dynamics. This paper provides a review of the current state of research on modeling linear carbon structures and related materials. We show that even though the “static” properties of carbon chains (mechanical strength, thermal conduction, band gaps, and phonon spectra) are extensively described, there are only a few simulations of the synthesis processes that constitute the next challenge in 1D research.

Density Functional Theory Study of Finite Carbon Chains

ACS Nano ◽  
2009 ◽  
Vol 3 (11) ◽  
pp. 3788-3794 ◽  
Author(s):  
XiaoFeng Fan ◽  
Lei Liu ◽  
JianYi Lin ◽  
ZeXiang Shen ◽  
Jer-Lai Kuo
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Carbon Chains

scholarly journals Liquid-state properties from first-principles density functional theory calculations: Static properties

2010 ◽  
Vol 82 (14) ◽  
Author(s):  
Nicolas Bock ◽  
Erik Holmström ◽  
Travis B. Peery ◽  
Raquel Lizárraga ◽  
Eric D. Chisolm ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Liquid State ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Static Properties ◽  
Functional Theory

scholarly journals Quantum transport in zigzag graphene nanoribbon decorated with a phenanthrene molecule

2021 ◽  
Author(s):  
Bo Jiang ◽  
Qing-Yuan Chen ◽  
Jinlong Luo ◽  
Yifen Zhao ◽  
GuoJun Jin ◽  
...  
Keyword(s):  
Quantum Transport ◽  
Density Functional ◽  
Physical Mechanism ◽  
Differential Resistance ◽  
Graphene Nanoribbon ◽  
Hybrid Structures ◽  
Differential Conductance ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Carbon Chains

Abstract By using the first principles calculations which combine density functional theory and nonequilibrium Green's function, we investigate the nanoscopic quantum transport of three hybrid structures consisting of a phenanthrene (PHE) molecule and a zigzag graphene nanoribbon (ZGNR). It is found that after decorated with the PHE molecule, the ZGNRs with the odd (even) zigzag carbon chains show the conductance reduction (enhancement), respectively. With the increase of the number of carbon chains, this odd-even difference will disappear. Moreover, negative differential resistance behavior can also be found in the hybrid structures consisting of the PHE molecule and the antisymmetric ZGNR. Finally, the differential conductance, transmission spectra, and molecular projection self-consistent Hamiltonian are used to explain the physical mechanism clearly. Accordingly, the proposed structures could have broad applications in the design of molecular nanodevices.

scholarly journals The Effects of Carbon Content on the Anisotropic Deformation Mechanism of Boron Carbide

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1861
Author(s):  
Jun Li ◽  
Lisheng Liu ◽  
Shuang Xu ◽  
Jinyong Zhang ◽  
Yuanli Wu
Keyword(s):  
Carbon Content ◽  
Deformation Mechanism ◽  
Density Functional ◽  
Deformation Mechanisms ◽  
Structural Failure ◽  
Functional Theory ◽  
Carbon Chains ◽  
The Density Functional Theory ◽  
Rhombohedral Symmetry ◽  
Anisotropic Deformation

The effects of carbon content on the mechanical properties and deformation mechanisms of boron carbides were investigated by first-principles calculations, based on the density functional theory. The B12–CBC (13.33 at % C) and B10 C 2 P –CC (28.75 at % C) were studied and then compared with the deformation of regular B11CP–CBC (20.0 at % C). The results show the B10 C 2 P –CC, which has the lowest carbon content, has the highest strength and hardness as well as the lowest toughness. With the increase of carbon content, the rhombohedral symmetry will be broken and the three-atoms chains will be replaced by diatomic carbon chains. These changes may have an influence on their anisotropic deformation mechanisms. For the B12–CBC, the destruction of icosahedra without bending three-atom chains causes structural failure for compression along the c axis; while for compression along the a axis, new B–B bonds are formed, causing an unrecoverable deformation; then it is gradually destroyed until full destruction. For the B10 C 2 P –CC, the anisotropic deformation mechanism is not obvious. For both loading directions, the breakage of B–CP bonds causes the stress to drop, suggesting that the structure is beginning to be destroyed. Finally, the icosahedra are fully destroyed, resulting in structural failure.

Theoretical Study of Structural, Elastic Properties and Phase Transitions of Cu2ZnSnS4

2014 ◽  
Vol 1058 ◽  
pp. 113-117 ◽  
Author(s):  
Yi Feng Zhao ◽  
Zu Ming Liu ◽  
De Cong Li
Keyword(s):  
Phase Transitions ◽  
Elastic Properties ◽  
Density Functional ◽  
Theoretical Work ◽  
Structure Stability ◽  
Ground State Structure ◽  
Preparation Technology ◽  
Functional Theory ◽  
Unstable Phase ◽  
Total Energies

The total energy, the electronic properties, phase transitions, and elastic properties of Cu2ZnSnS4(CZTS) in the three structures are investigated by first-principles calculations based on density functional theory. Results show that the total energies of stannite (ST) and primitive-mixed CuAu (PMCA) structures are higher than that of kesterite-type (KS), and the KS is the ground state structure. Relationships between enthalpy and pressure of the KS, ST and PMCA structure of CZTS are also investigated at 0 K, since the pressure can have profound impacts on the electronic structure, possible phase transitions and structure stability. And results also show that KS structure is always the most stable; ST is the second; and the PMCA structure is the most unstable; phase transitions of three structures could not occur in high pressure. The high ratios of shear modulus to bulk modulus (G/B) indicate that CZTS compounds in three types have ductile behaviors. The Poisson ratios for the three structures are from 0.27 to 0.31, which again proves that all structures of CZTS have better plasticity. The results can increase more hints about further research directions, and these effects can play an important role in future experimental preparation technology and theoretical work of CZTS materials.

Structure and stability of complex metal hydrides – theoretical approach

2004 ◽  
Vol 837 ◽  
Author(s):  
Zbigniew Łodziana ◽  
Tejs Vegge
Keyword(s):  
Ground State ◽  
Density Functional ◽  
Metal Hydrides ◽  
Functional Theory ◽  
Complex Metal ◽  
Phonon Spectra ◽  
Atomic Vibrations ◽  
Ground State Structures ◽  
Ground State Energies ◽  
Annealing Method

AbstractIn this paper systematic approach to study the structural stability of the complex hydride, LiBH4 is presented. The ground state energies of various symmetry structures are determined by means of Density Functional Theory. Simulated annealing method is used to confirm if ground state structures represent real energy minima. The vibrational spectrum and temperature dependence of the free energy of the structures with the lowest energies is determined. Calculated Raman active modes for three symmetries are presented. We show that at high temperatures LiBH4 possesses monoclinic symmetry and some of the low energy structures are unstable with respect to atomic vibrations. Our studies point to the necessity of calculation of the phonon spectra for complex metal hydrides that contain covalently bounded hydrogen.

DFT STUDY ON POLYDIACETYLENES AND THEIR DERIVATIVES

2009 ◽  
Vol 08 (05) ◽  
pp. 871-880
Author(s):  
BIN HUANG ◽  
XING CHEN ◽  
ZEXING CAO
Keyword(s):  
Density Functional ◽  
Oscillator Strengths ◽  
Functional Theory ◽  
Triple Bonds ◽  
Carbon Chains ◽  
Vertical Transition ◽  
Structural And Electronic Properties ◽  
Equilibrium Geometries ◽  
Homo Lumo ◽  
Optimized Geometries

Optimized geometries and vibrational frequencies of polydiacetylenes (PDAs) and their derivatives were studied by density functional calculations at the B3LYP/6-31G* level. The time-dependent density functional theory was used to determine their vertical transition energies and corresponding oscillator strengths. Calculations show that different side groups in these linear carbon chains can significantly modify their structural and electronic properties, whereas the effect of terminal substitution is negligible. Predicted equilibrium geometries indicate that the single, double, and triple bonds of PDAs and their derivatives are almost unchanged as the chain increases, showing a remarkable character of localized bond. The periodic boundary condition calculations reveal that the strongest adsorption for the infinite chain of PDA appears at 723 nm, and the HOMO → LUMO excitation is responsible for this strong electronic transition.

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