scholarly journals Assessment of Functionals for First-Principle Studies of the Structural and Electronic Properties ofδ-Bi2O3

2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
D. H. Galván ◽  
R. Núñez-González ◽  
R. Rangel ◽  
P. Alemany ◽  
A. Posada-Amarillas
Keyword(s):  
Band Structure ◽  
Charge Density ◽  
Electronic Properties ◽  
Density Of States ◽  
Lattice Parameter ◽  
Experimental Result ◽  
Ionic Character ◽  
High Symmetry ◽  
Density Profiles ◽  
Structural And Electronic Properties

Fully relativistic full-potential density functional calculations with an all-electron linearized augmented plane waves plus local orbitals method were carried out to perform a comparative study on the structural and electronic properties of the cubic oxideδ-Bi2O3phase, which is considered as one of the most promising materials in a variety of applications including fuel cells, sensors, and catalysts. Three different density functionals were used in our calculations, LDA, the GGA scheme in the parametrization of Perdew, Burke, and Ernzerhof (PBE96), and the hybrid scheme of Perdew-Wang B3PW91. The examined properties include lattice parameter, band structure and density of states, and charge density profiles. For this modification the three functionals reveal the characteristics of a metal and the existence of minigaps at high symmetry points of the band structure when spin-orbit coupling is taken into account. Density of states exhibits hybridization of Bi 6s and O 2p orbitals and the calculated charge density profiles exhibit the ionic character in the chemical bonding of this compound. The B3PW91 hybrid functional provided a better agreement with the experimental result for the lattice parameter, revealing the importance of Hartree-Fock exchange in this compound.

scholarly journals Study of Structural and Electronic Properties of Intercalated Transition Metal Dichalcogenides Compound MTiS2 (M = Cr, Mn, Fe) by Density Functional Theory

2021 ◽  
Keyword(s):  
Transition Metal ◽  
Band Structure ◽  
Electronic Properties ◽  
Density Of States ◽  
Density Functional ◽  
Transition Metal Dichalcogenides ◽  
Energy Band Structure ◽  
Functional Theory ◽  
Structural And Electronic Properties ◽  
Metal Dichalcogenides

In the present work, we have studied intercalated Transition Metal Dichalcogenides (TMDC) MTiS2 compounds (M = Cr, Mn, Fe) by Density Functional Theory (DFT) with Generalized Gradient Approximation (GGA). We have computed the structural and electronic properties by using first principle method in QUANTUM ESPRESSO computational code with an ultra-soft pseudopotential. A guest 3d transition metal M (viz; Cr, Mn, Fe) can be easily intercalated in pure transition metal dichalcogenides compound like TiS2. In the present work, the structural optimization, electronic properties like the energy band structure, density of states (DoS), partial or projected density of states (PDoS) and total density of states (TDoS) are reported. The energy band structure of MTiS2 compound has been found overlapping energy bands in the Fermi region. We conclude that the TiS2 intercalated compound has a small band gap while the doped compound with guest 3d-atom has metallic behavior as shown form its overlapped band structure.

AB INITIO CALCULATION OF THE ELECTRONIC AND MECHANICAL PROPERTIES OF TRANSITION METALS AND THEIR NITRIDES

2004 ◽  
Vol 18 (07n08) ◽  
pp. 281-289 ◽  
Author(s):  
CHENG-BIN LI ◽  
MING-KAI LI ◽  
FU-QING LIU ◽  
XIANG-JUN FAN
Keyword(s):  
Mechanical Properties ◽  
Transition Metals ◽  
Ab Initio Calculations ◽  
Charge Density ◽  
Ab Initio ◽  
Electronic Properties ◽  
Density Of States ◽  
Ab Initio Calculation ◽  
Structural And Electronic Properties

The results of ab initio calculations of the bulk moduli (B0) and related structural and electronic properties of selected transition metals and their nitrides are presented. There is a correlation between B0 and valence charge density. B0 does not vary monotonically with the addition of d electrons. Charge density and density of states (DOS) plots enable us to explain it.

FIRST-PRINCIPLE STUDY OF STRUCTURAL AND ELECTRONIC PROPERTIES OF CUBIC STRONTIUM TITANATE

2013 ◽  
Vol 22 ◽  
pp. 340-345
Author(s):  
AVINASH DAGA ◽  
SMITA SHARMA ◽  
K. S. SHARMA
Keyword(s):  
Bulk Modulus ◽  
Charge Density ◽  
Electronic Properties ◽  
Local Density ◽  
Computer Code ◽  
Lattice Parameter ◽  
Plane Wave Expansion ◽  
Structural And Electronic Properties ◽  
Calculated Lattice Parameter ◽  
Good Agreement

We have performed ab-initio investigation of SrTiO3 with cubic structure, and have computed its structural and electronic properties. The calculations are performed using a plane wave expansion within the local density approximation and the pseudopotential approximation. Results are given for the lattice constant, bulk modulus and charge density. The lattice parameter and bulk modulus calculated for SrTiO3within LDA are 3.908 Å and 184.6832 GPa respectively. It is found that the calculated lattice parameter and bulk modulus are in good agreement with the available experimental data. The charge density plots show higher accumulation of charge around the boundary and corners. All these calculations have been carried out using ABINIT computer code.

STRUCTURAL AND ELECTRONIC PROPERTIES OF CARBON NANOTUBES

2000 ◽  
Vol 11 (01) ◽  
pp. 175-182 ◽  
Author(s):  
ŞAKIR ERKOÇ
Keyword(s):  
Carbon Nanotubes ◽  
Electronic Properties ◽  
Molecular Mechanics ◽  
Density Of States ◽  
Linear Dependence ◽  
The Other ◽  
Tube Length ◽  
Single Wall Carbon Nanotubes ◽  
Tube Size ◽  
Structural And Electronic Properties

The structural and electronic properties of optimized open-ended single-wall carbon nanotubes with zigzag geometry have been investigated. The calculations were performed using molecular mechanics, extended Hückel, and AM1–RHF semiempirical molecular orbital methods. It has been found that the density of states of the zigzag model is sensitive to the tube size and changes as the tube length increases. On the other hand the energetics of the tube shows an almost linear dependence to the tube length, and a converging characteristics with respect to the number of hexagons forming the tube.

scholarly journals Strong correlation between electronic bonding network and critical temperature in hydrogen-based superconductors

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Francesco Belli ◽  
Trinidad Novoa ◽  
J. Contreras-García ◽  
Ion Errea
Keyword(s):  
Critical Temperature ◽  
Physical Properties ◽  
Fermi Level ◽  
Electronic Properties ◽  
Density Of States ◽  
Strong Correlation ◽  
Critical Temperatures ◽  
Structural And Electronic Properties ◽  
Superconducting Compounds ◽  
Better Than

AbstractBy analyzing structural and electronic properties of more than a hundred predicted hydrogen-based superconductors, we determine that the capacity of creating an electronic bonding network between localized units is key to enhance the critical temperature in hydrogen-based superconductors. We define a magnitude named as the networking value, which correlates with the predicted critical temperature better than any other descriptor analyzed thus far. By classifying the studied compounds according to their bonding nature, we observe that such correlation is bonding-type independent, showing a broad scope and generality. Furthermore, combining the networking value with the hydrogen fraction in the system and the hydrogen contribution to the density of states at the Fermi level, we can predict the critical temperature of hydrogen-based compounds with an accuracy of about 60 K. Such correlation is useful to screen new superconducting compounds and offers a deeper understating of the chemical and physical properties of hydrogen-based superconductors, while setting clear paths for chemically engineering their critical temperatures.

COMPARATIVE STUDY OF THE STRUCTURAL AND ELECTRONIC PROPERTIES OF BN(5, 5) AND C(5, 5) NANOTUBES UNDER PRESSURE

2010 ◽  
Vol 24 (24) ◽  
pp. 4851-4859
Author(s):  
KAIHUA HE ◽  
GUANG ZHENG ◽  
GANG CHEN ◽  
QILI CHEN ◽  
MIAO WAN ◽  
...  
Keyword(s):  
High Pressure ◽  
Comparative Study ◽  
Charge Density ◽  
Band Gap ◽  
Electronic Properties ◽  
Cross Section ◽  
First Principles ◽  
First Principles Calculations ◽  
Zinc Blende ◽  
Structural And Electronic Properties

The structural and electronic properties of BN(5, 5) and C(5, 5) nanotubes under pressure are studied by using first principles calculations. In our study range, BN(5, 5) undergoes obvious elliptical distortion, while for C(5, 5) the cross section first becomes an ellipse and then, under further pressure, is flattened. The band gap of BN(5, 5) decreases with increasing pressure, which is inverse to that of zinc blende BN, whereas for C(5, 5) the metallicity is always preserved under high pressure. The population of charge density indicates that intertube bonding is formed under pressure. We also find that BN(5, 5) may collapse, and a new polymer material based on C(5, 5) is formed by applying pressure.

FIRST-PRINCIPLE CALCULATION OF STRUCTURAL AND ELECTRONIC PROPERTIES OF ZINC-BLENDE ByAlxGa1-x-yN MATCHED TO AlN SUBSTRATE

2012 ◽  
Vol 26 (24) ◽  
pp. 1250159 ◽  
Author(s):  
LAKHDAR DJOUDI ◽  
ABDELHADI LACHEBI ◽  
BOUALEM MERABET ◽  
HAMZA ABID
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Strong Dependence ◽  
Theoretical Data ◽  
Lattice Parameter ◽  
Full Potential ◽  
Generalized Gradient ◽  
First Principle Calculation ◽  
Zinc Blende ◽  
Structural And Electronic Properties

The full-potential linearized augmented plane wave method (FP-LAPW) within density functional theory, using the generalized gradient approximation, is used to study the structural and electronic properties of zinc-blende B y Al x Ga 1-x-y N quaternary alloys that match the lattice of an AlN substrate. The range of compositions, for which the lattice of the alloy matches AlN , is determined. Our calculated band structure, density of states, electron density and lattice parameter for B y Al x Ga 1-x-y N allow to accurately evaluate the profound effect that the incorporation of small amounts of Boron have on structural and electronic properties of Al x Ga 1-x N alloys. A comparison of the ground state properties with the available experimental and theoretical data is made for the compounds related to B y Al x Ga 1-x-y N and of the Al x Ga 1-x N alloys. The results show a strong dependence of the band gap (as well as the lattice parameter) on the Boron content, which might make B y Al x Ga 1-x-y N materials promising and useful for optoelectronic applications.

First-Principles Study on Electronic Structure of 15R-SiC Polytypes

2014 ◽  
Vol 971-973 ◽  
pp. 77-80 ◽  
Author(s):  
Fu Chun Zhang ◽  
Ying Gao ◽  
Hong Wei Cui ◽  
Xing Xiang Ruan ◽  
Wei Hu Zhang
Keyword(s):  
Electronic Structure ◽  
Band Structure ◽  
Charge Density ◽  
Band Gap ◽  
Density Functional ◽  
Covalent Bond ◽  
Lattice Parameter ◽  
Pseudopotential Approach ◽  
Structure Density ◽  
Indirect Band Gap

To study the geometrical and electronic structure of 15R-SiC polytypes, the lattice parameter, band structure, density of states (DOS) and charge density of 15R-SiC are calculated by using density functional theory based on the plane wave pseudopotential approach, and electronic structure and ground properties of 15R-SiC are investigated by the calculated band structure and DOS, the results show that 15R-SiC is an indirect band gap semiconductor, with calculated indirect band gap width being 2.16 eV and band gap dependent on Si 3p and C 2p states. While charge density results show that Si-C bond is a hybrid bond semiconductor strong in covalent bond and weak in ionicity, characterized by intense sp3 hybrid characteristics, which is in accordance with the experimental results. The above mentioned results are considered as theoretical reference for design and application of SiC polytype materials.

Structural and electronic properties of zincblende phase of TlxGa1−x AsyP1−y quaternary alloys: First-principles study

Open Physics ◽  
2013 ◽  
Vol 11 (12) ◽  
Author(s):  
Sinem Gulebaglan ◽  
Emel Dogan ◽  
Murat Aycibin ◽  
Mehmet Secuk ◽  
Bahattin Erdinc ◽  
...  
Keyword(s):  
Band Structure ◽  
Band Gap ◽  
Electronic Properties ◽  
First Principles ◽  
Local Density ◽  
Density Approximation ◽  
Quaternary Alloys ◽  
Lattice Constants ◽  
Vegard’S Law ◽  
Structural And Electronic Properties

AbstractUsing the first-principles band-structure method, we have calculated the structural and electronic properties of zincblende TlAs, TlP, GaAs and GaP compounds and their new semiconductor TlxGa1−x AsyP1−y quaternary alloys. Structural properties of these semiconductors are obtained with the Perdew and Wang local-density approximation. The lattice constants of TlxGa1−x As, TlxGa1−x P ternary and TlxGa1−x AsyP1−y quaternary alloys were composed by Vegard’s law. Our investigation on the effect of the doping (Thallium and Arsenic) on lattice constants and band gap shows a non-linear dependence for TlxGa1−x AsyP1−y quaternary alloys. The band gap of TlxGa1−x AsyP1−y , E g(x, y) concerned by the compositions x and y. To our awareness, there is no theoretical survey on TlxGa1−x AsyP1−y quaternary alloys and needs experimental verification.

STRUCTURAL AND ELECTRONIC PROPERTIES AND PHONONS OF PLATINUM NITRIDES BY DENSITY FUNCTIONAL THEORY

2011 ◽  
Vol 25 (11) ◽  
pp. 1543-1551 ◽  
Author(s):  
PRAFULLA K. JHA ◽  
SANJAY D. GUPTA ◽  
SANJEEV K. GUPTA ◽  
DAVOR KIRIN
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Calculated Data ◽  
High Symmetry ◽  
Phonon Modes ◽  
Functional Theory ◽  
Unified Study ◽  
Structural And Electronic Properties ◽  
Zone Centre ◽  
Two Phases

Using first principles calculations, we provide here a unified study of structural and electronic properties along with frequency of phonon modes at some high-symmetry points of the Brillouin zone for the noble metal nitride platinum nitride (PtN) by using PWSCF code. Our calculations are performed for two phases viz. zincblende and rocksalt. The present study predicts the zincblende structure as the most probable crystal structure out of two, besides it being metallic. The calculated structural and electronic properties and zone centre phonon modes are in good agreement with the experimental and other calculated data.

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