Electronic and phononic properties of V2AlC via first principles

2013 ◽  
Vol 91 (10) ◽  
pp. 822-825 ◽  
Author(s):  
Z.J. Yang ◽  
J. Li ◽  
R.F. Linghu ◽  
X.S. Song ◽  
X.L. Cheng ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Electron Density ◽  
First Principles ◽  
Density Functional ◽  
Phonon Dispersion ◽  
Structural Instability ◽  
Difference Electron Density ◽  
Functional Theory ◽  
Net Charge ◽  
Electron Density Of States

The electronic and phononic properties of V2AlC have been extensively studied using ab initio pseudopotential density functional theory. Our investigations revealed that the longest V–V bond and its least variations have led to the stiffer c axis. The nearly unchanged net charge of the C atom under pressure has led to nearly unchanged overlapped populations along the C–V bond. The obvious charge transfer of V → Al has induced significant variations of the overlapped populations along Al–V and V–V bonds. An anomalous variation of charge transfer between V and Al atoms and V–V bond populations at about 700 GPa has been revealed, which may relate to its structural instability at about 731 GPa. Previously calculated structural instability at about 731 GPa has been successfully confirmed by the present phonon dispersion curve. The bonding natures are also studied by the electron density difference, electron density of states, and the energy band structure.

A novel mechanism of spin-orientation dependence of O2 reactivity from first principles methods

2017 ◽  
Vol 7 (5) ◽  
pp. 1040-1044 ◽  
Author(s):  
M. C. S. Escaño ◽  
H. Kasai
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Transition State ◽  
First Principles ◽  
Density Functional ◽  
Orientation Dependence ◽  
Coupling Mechanism ◽  
Spin Moment ◽  
Spin Orientation ◽  
Functional Theory

A novel mechanism of oxygen reaction on a metal surface beyond the present charge transfer or hybridization mechanism, spin-orientation dependence via a coupling mechanism due to the finite spin moment of O2 at the transition state, is obtained using a combination of spin density functional theory (SDFT) and constrained DFT.

First-Principles Study on Initial Oxidation of NiAl(110)

2007 ◽  
Vol 546-549 ◽  
pp. 1455-1460 ◽  
Author(s):  
Jun Min Hu ◽  
Jia Xiang Shang ◽  
Yue Zhang ◽  
Chun Gen Zhou ◽  
Hui Bin Xu
Keyword(s):  
Density Functional Theory ◽  
Charge Transfer ◽  
Oxygen Atom ◽  
Chemical Bond ◽  
First Principles ◽  
Density Functional ◽  
Bridge Site ◽  
Initial Oxidation ◽  
Functional Theory ◽  
Oxidation Stage

The oxygen atom adsorption at Al-Al bridge, Ni-Ni bridge, Al top and Ni top site on the NiAl(110) surface by first-principles method within density functional theory has been studied in this paper. It has been found that the preferred adsorption position of the oxygen was at the Al-Al bridge site then the Ni-Ni bridge site. The charge transfer took place obviously between the O atom and the nearest Al atoms, but no charge transferred from the nearest Ni atoms to O atom. For the Al-Al (Ni-Ni) bridge adsorption site, the bond lengths of Al-O and Ni-O were about 1.741 Å (1.700Å) and 2.369Å (2.012Å), respectively, which means that the Al atom is easier to be oxidized than the Ni atom. It is revealed that the Al atom oxidized selectively and the chemical bond formed between the O ion and the nearest Al ions during the initial oxidation stage.

First-principles study on the structural, elastic and electronic properties of the four Si3Sb4 compounds

2019 ◽  
Vol 33 (05) ◽  
pp. 1950047
Author(s):  
Ruike Yang ◽  
Bao Chai ◽  
Qun Wei ◽  
Minhua Xue ◽  
Ye Zhou
Keyword(s):  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Phonon Dispersion ◽  
Elastic Anisotropy ◽  
Functional Theory ◽  
Shear Moduli ◽  
Young’S Moduli ◽  
Poisson's Ratios ◽  
Poisson’S Ratios

For novel [Formula: see text]-Si3Sb4, pseudocubic-Si3Sb4, cubic-Si3Sb4 and [Formula: see text]-Si3Sb4, the structural, elastic and electronic properties are investigated using first-principles density functional theory (DFT). The elastic constants and phonon dispersion spectra show that they are mechanically and dynamically stable. The bulk moduli, shear moduli, Young’s moduli, Poisson’s ratios and Pugh ratios for the four compounds have been calculated. The bulk moduli indicate that the bond strength of [Formula: see text]-Si3Sb4 is stronger than others. The values of the Poisson’s ratios and Pugh ratios show that pseudocubic-Si3Sb4 is the stiffest among the four Si3Sb4 compounds. Tetragonal Si3Sb4 are more brittle than cubic Si3Sb4. For the four Si3Sb4 compounds, the elastic anisotropies are analyzed via the anisotropic indexes and the 3D surface constructions. The [Formula: see text]-Si3Sb4 elastic anisotropy is stronger than others and the [Formula: see text]-Si3Sb4 is weaker than others. The calculated band structures show that they exhibit metallic features. The results of their TDOS show that there are many similarities. The peaks of TDOS are derived from the contributions of Si “s”, Si “p”, Sb “s” and Sb “p” states.

First-principles study of nitrogen and carbon monoxide adsorptions on silicene

2016 ◽  
Vol 30 (25) ◽  
pp. 1650176 ◽  
Author(s):  
Shuying Zhong ◽  
Fanghua Ning ◽  
Fengya Rao ◽  
Xueling Lei ◽  
Musheng Wu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Carbon Monoxide ◽  
Charge Transfer ◽  
First Principles ◽  
Density Functional ◽  
Co Adsorption ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Adsorption Energies ◽  
Charge Calculations

Atomic adsorptions of N, C and O on silicene and molecular adsorptions of N2 and CO on silicene have been investigated using the density functional theory (DFT) calculations. For the atomic adsorptions, we find that the N atom has the most stable adsorption with a higher adsorption energy of 8.207 eV. For the molecular adsorptions, we find that the N2 molecule undergoes physisorption while the CO molecule undergoes chemisorption, the corresponding adsorption energies for N2 and CO are 0.085 and 0.255 eV, respectively. Therefore, silicene exhibits more reactivity towards the CO adsorption than the N2 adsorption. The differences of charge density and the integrated charge calculations suggest that the charge transfer for CO adsorption ([Formula: see text]0.015[Formula: see text]) is larger than that for N2 adsorption ([Formula: see text]0.005[Formula: see text]). This again supports that CO molecule is more active than N2 molecule when they are adsorbed onto silicene.

First-principles investigation of MoS2 monolayer adsorbed on SiO2 (0001) Surface

2017 ◽  
Vol 31 (25) ◽  
pp. 1750229 ◽  
Author(s):  
Xiangying Su ◽  
Hongling Cui ◽  
Weiwei Ju ◽  
Yongliang Yong ◽  
Xiaohong Li
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Charge Transfer ◽  
First Principles ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Interlayer Spacing ◽  
Covalent Bonds ◽  
Functional Theory ◽  
Mos2 Monolayer

In this paper, the geometric and electronic structure of MoS2 monolayer (ML) adsorbed on SiO2 (0001) surface were studied by using density functional theory calculations. The calculated interfacial binding energy shows that the MoS2/SiO2 hybrid system is stable. MoS2 ML is bound to the SiO2 surface with a big interlayer spacing and no covalent bonds form at the interface. The study of the density of states and the charge transfer indicates that the interaction between MoS2 ML and the SiO2 substrate is very weak. As a result, the electronic properties of MoS2 ML are almost not affected by the SiO2 substrate. This work will be beneficial to the design of MoS2 ML-based devices where a substrate is needed.

Phase transformation, ionic diffusion, and charge transfer mechanisms of KVOPO4 in potassium ion batteries: first-principles calculations

2018 ◽  
Vol 6 (33) ◽  
pp. 16228-16234 ◽  
Author(s):  
Ruqian Lian ◽  
Dashuai Wang ◽  
Xing Ming ◽  
Rongyu Zhang ◽  
Yingjin Wei ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Phase Transformation ◽  
Charge Transfer ◽  
First Principles ◽  
Density Functional ◽  
Potassium Ion ◽  
Ionic Diffusion ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Transfer Mechanisms

First-principles calculations based on density functional theory were performed to investigate the electrochemical properties of K1−xVOPO4 in potassium-ion batteries (KIBs).

STRUCTURAL, MECHANICAL AND LATTICE DYNAMICAL STABILITY OF AgC AND AuC COMPOUNDS: A FIRST PRINCIPLES STUDY

2012 ◽  
Vol 26 (17) ◽  
pp. 1250107 ◽  
Author(s):  
ENGIN ATESER ◽  
HAVVA BOGAZ OZISIK
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Phonon Dispersion ◽  
Correlation Effects ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Generalized Gradient Approximation ◽  
Dynamical Properties ◽  
Stable Structures

Based on density functional theory, we have studied the structural stability, elastic, mechanical and lattice dynamical properties of AgC and AuC compounds for various structures: NaCl ( B1 ), CsCl ( B2 ), ZnS ( B3 ), wurtzite ( B4 ), WC ( B h), NiAs ( B8 1) and CdTe . Generalized gradient approximation has been used for modeling exchange-correlation effects. The second-order elastic constants and related polycrystalline properties (bulk modulus, shear modulus, Young's modulus, Poisson's ratio, Debye temperature and sound velocities) have been calculated and discussed. We have also calculated phonon dispersion and phonon density of states of these compounds in all considered structures. According to the results, we found that, AgC compound is mechanically and dynamically stable in B8 1, B1 and B4 structures. Our results indicate that B81 and B3 are the candidate stable structures energetically, mechanically and dynamically for AgC and AuC compounds, respectively.

First low-spin carbodiimide, Fe2(NCN)3, predicted from first-principles investigations

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Hao Chen ◽  
Hongping Xiang
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Physical Properties ◽  
First Principles ◽  
Title Compound ◽  
Density Functional ◽  
Phonon Dispersion ◽  
Functional Theory ◽  
Half Metallic ◽  
Phonon Dispersion Relations

Abstract The structural stability and physical properties of the Fe(III) carbodiimide Fe2(NCN)3 were studied by use of density functional theory. The results indicate that Fe2(NCN)3 (space group R 3 ‾ c $R‾{3}c$ ) is stable both thermodynamically and mechanically. The electronic structure in combination with the phonon dispersion relations suggest that the title compound should be ferromagnetic and half-metallic, and that the Fe3+ ions are in the low-spin state.

scholarly journals First Principles Investigations on the Electronic and Magnetic Properties of La4Ba2Cu2O10

2016 ◽  
Vol 3 (1) ◽  
pp. 89 ◽  
Author(s):  
Shalika Ram Bhandari ◽  
Ram Kumar Thapa ◽  
Madhav Prasad Ghimire
Keyword(s):  
Density Functional Theory ◽  
Magnetic Properties ◽  
Charge Transfer ◽  
Magnetic Moment ◽  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Dft Calculation ◽  
Functional Theory ◽  
Electronic And Magnetic Properties

<p>Electronic and magnetic properties of La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub> had been studied by first-principles density functional theory (DFT). Based on the DFT calculation La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub> is found to have a ferromagnetic (FM) ground state. The material undergo charge-transfer type insulator to Mott-Hubbard type insulator transition which happens due to strong correlation in La-4f and Cu-3d states. Our results show that the 3d electrons of Cu hybridize strongly with O-2p states near the Fermi level giving rise to the insulating state of La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub>. Our study suggests that the enhanced magnetic moment is a result of itinerant exchange rather than the exchange interaction involving individual ions of Cu atoms. The total magnetic moment calculated in the present studies is 2 μ<sub>B</sub> per unit cell for La<sub>4</sub>Ba<sub>2</sub>Cu<sub>2</sub>O<sub>10</sub>.</p><p>Journal of Nepal Physical Society Vol.3(1) 2015: 89-96</p>

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