Ab initio determination of the valence electron distribution in the average structure of the incommensurately modulated calaverite AuTe2

2001 ◽  
Vol 57 (5) ◽  
pp. 633-637 ◽  
Author(s):  
Razvan Caracas ◽  
Xavier Gonze
Keyword(s):  
Electron Density Distribution ◽  
Density Functional ◽  
Valence Electron ◽  
Electronic Band Structure ◽  
Chemical Bonds ◽  
Electronic Band ◽  
Functional Theory ◽  
Average Structure ◽  
Valence Electron Density

The valence-electron density distribution of the average structure of incommensurately modulated calaverite, AuTe2, has been computed using density-functional theory. High-density regions, centered around the Au and Te atoms, are not spheric, but present charge concentrations along the Au—Te and Te—Te bonds. The electronic band structure and its corresponding density of states reveal the presence of three electronic band groups, constituted mainly by Te 5s, Au 5d and hybrids of Te 6p + Au 6s + Au 5d orbitals. The electrons belonging to the last block are responsible for the chemical bonds.

scholarly journals First-Principles Determination of the Polarizabilities of Carbon Tubules as a Function of Length

1994 ◽  
Vol 349 ◽  
Author(s):  
Andrew A. Quong ◽  
Mark R. Pederson
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Valence Electron ◽  
Local Density ◽  
Density Approximation ◽  
Functional Theory ◽  
Size Dependent ◽  
The Density Functional Theory ◽  
Linear And Nonlinear

ABSTRACTWe use the local-density-approximation to the density-functional theory to determine the axial polarizabilities of fullerene tubules as a function of length and winding topologies. Specifically, we present linear polarizabilities for tubules of composition C12H24, C36H24, C40H20 and C60H24. The size-dependent variation in the dipole-coupled gaps between pairs of occupied and unoccupied levels leads to enhancements in the polarizability per valence electron as the length of the tubule increases. The results are compared to recent densityfunctional based calculations of the linear and nonlinear polarizabilities for fullerene and benzene molecules.

scholarly journals Structural, Electronic and Vibrational Properties of YAl3(BO3)4

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 545 ◽  
Author(s):  
Aleksandr S. Oreshonkov ◽  
Evgenii M. Roginskii ◽  
Nikolai P. Shestakov ◽  
Irina A. Gudim ◽  
Vladislav L. Temerov ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Band Gap ◽  
Density Functional ◽  
Dielectric Material ◽  
Electronic Band Structure ◽  
Vibrational Properties ◽  
Electronic Band ◽  
Functional Theory ◽  
Dynamical Properties ◽  
Indirect Band Gap

The crystal structure of YAl3(BO3)4 is obtained by Rietveld refinement analysis in the present study. The dynamical properties are studied both theoretically and experimentally. The experimental Raman and Infrared spectra are interpreted using the results of ab initio calculations within density functional theory. The phonon band gap in the Infrared spectrum is observed in both trigonal and hypothetical monoclinic structures of YAl3(BO3)4. The electronic band structure is studied theoretically, and the value of the band gap is obtained. It was found that the YAl3(BO3)4 is an indirect band gap dielectric material.

FIRST-PRINCIPLES STUDIES ON THE ELECTRONIC STRUCTURE OF LuPd2Si2

2009 ◽  
Vol 23 (32) ◽  
pp. 5929-5934 ◽  
Author(s):  
T. JEONG
Keyword(s):  
Band Structure ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Local Density ◽  
Spin Orbit Coupling ◽  
Electronic Band ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structure Scheme

The electronic band structure of LuPd 2 Si 2 was studied based on the density functional theory within local density approximation and fully relativistic schemes. The Lu 4f states are completely filled and have flat bands around -5.0 eV. The fully relativistic band structure scheme shows that spin–orbit coupling splits the 4f states into two manifolds, the 4f7/2 and the 4f5/2 multiplet.

scholarly journals Ab-initio study of the orthorhombic ndmno3 perovskite

2014 ◽  
Vol 70 (a1) ◽  
pp. C1806-C1806
Author(s):  
Samir Bentata ◽  
Bouabdellah Bouadjemi ◽  
Tayeb Lantri ◽  
Wissem Benstaali
Keyword(s):  
Density Functional ◽  
Electronic Band Structure ◽  
Total Density ◽  
Generalized Gradient ◽  
Electronic Band ◽  
Functional Theory ◽  
Half Metallic ◽  
Generalized Gradient Approximation ◽  
Ferromagnetic Ground State ◽  
Total Density Of States

We investigate the structural, electronic and magnetic properties of the orthorhombic Perovskite oxyde NdMnO3 through density-functional-theory (DFT) calculations using both generalized gradient approximation GGA+U, where U is on-site Coulomb interaction correction. The electronic band structure, the partial and total density of states (DOS) and the magnetic moment are determined. The results show a half-metallic ferromagnetic ground state for the orthorhombic NdMnO3.

Ab Initio Electronic Structure Studies of CuO Multiferroics

2012 ◽  
Vol 488-489 ◽  
pp. 129-132 ◽  
Author(s):  
C. Kanagaraj ◽  
Baskaran Natesan
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Metallic State ◽  
Magnetic Ground State ◽  
Electronic Band ◽  
Functional Theory ◽  
High Tc ◽  
Band Structure Calculations ◽  
Structure Calculations

We have performed detailed structural, electronic and magnetic properties of high - TC multiferroic CuO using first principles density functional theory. The total energy results revealed that AFM is the most stable magnetic ground state of CuO. The DOS and electronic band structure calculations show that in the absence of on-site Coulomb interaction (U), AFM structure of CuO heads to a metallic state. However, upon incorporating U in the calculations, a band gap of 1.2 eV is recovered. Furthermore, the Born effective charges calculated on Cu does not show any anomalous character.This suggests that the polarization seen in CuO could be attributed to the spin induced AFM ordering effect.

scholarly journals Intriguing electronic, optical and photocatalytic performance of BSe, M2CO2 monolayers and BSe–M2CO2 (M = Ti, Zr, Hf) van der Waals heterostructures

RSC Advances ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 42-52
Author(s):  
M. Munawar ◽  
M. Idrees ◽  
Iftikhar Ahmad ◽  
H. U. Din ◽  
B. Amin
Keyword(s):  
Density Functional Theory ◽  
Band Structure ◽  
Density Functional ◽  
Photocatalytic Performance ◽  
Electronic Band Structure ◽  
Van Der Waals ◽  
Density Functional Theory Calculations ◽  
Van Der Waals Heterostructures ◽  
Electronic Band ◽  
Functional Theory

Using density functional theory calculations, we have investigated the electronic band structure, optical and photocatalytic response of BSe, M2CO2 (M = Ti, Zr, Hf) monolayers and their corresponding BSe–M2CO2 (M = Ti, Zr, Hf) van der Waals heterostructures.

scholarly journals First Principles Study on Structural and Electronic Properties of Cubic (Pm3m) And Tetragonal (P4mm) ATiO3 (A=Pb, Sn)

2020 ◽  
Vol 17 (2) ◽  
pp. 149
Author(s):  
Nurakma Natasya Md Jahangir Alam ◽  
Nur Aisyah Ab Malik Marwan ◽  
Mohd Hazrie Samat ◽  
Muhammad Zamir Mohyedin ◽  
Nur Hafiz Hussin ◽  
...  
Keyword(s):  
Cross Section ◽  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Ferroelectric Materials ◽  
Lead Free ◽  
Electronic Band ◽  
Functional Theory ◽  
First Principles Study ◽  
Structural And Electronic Properties

Works are centered on exploring lead-free ferroelectric materials that have a comparable unique ns2 solitary pair electrons with Pb (II), for example, Sn (II) using the first-principles study. All counts were performed dependent on Density Functional Theory (DFT) that has been executed in CASTEP. GGA-PBE displays the most exact qualities for cross-section parameters concerning exploratory qualities for both cubic PbTiO3. In the interim, GGA-PBEsol functional is exact for tetragonal PTO. The electronic band structure and density of states show the presence of hybridizations between anion O 2p and cation Pb 6s/Sn 5s unique solitary pair in tetragonal PTO and SnTO stage.

Structural, electronic, optical and thermal properties of CuXTe2 (X=Al, Ga, In) compounds: An ab-initio study

2019 ◽  
Vol 33 (07) ◽  
pp. 1950045
Author(s):  
R. Mahdjoubi ◽  
Y. Megdoud ◽  
L. Tairi ◽  
H. Meradji ◽  
Z. Chouahda ◽  
...  
Keyword(s):  
Thermal Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Full Potential ◽  
Electronic Band ◽  
Functional Theory ◽  
Thermodynamic Conditions ◽  
Structure Density ◽  
First Time ◽  
Linearized Augmented Plane Wave

First-principles calculations of the structural, electronic, optical and thermal properties of chalcopyrite CuXTe2 (X[Formula: see text]=[Formula: see text]Al, Ga, In) have been performed within density functional theory using the full-potential linearized augmented plane wave (FP-LAPW) method, by employing for the exchange and correlation potential the approximations WC-GGA and mBJ-GGA. The effect of X cations replacement on the structural, electronic band structure, density of states and optical properties were highlighted and explained. Our results are in good agreement with the previous theoretical and experimental data. As far as we know, for the first time we find the effects of temperature and pressure on thermal parameters of CuAlTe2 and CuGaTe2 compounds. Thermal properties are very useful for optimizing crystal growth, and predict photovoltaic applications on extreme thermodynamic conditions.

PRESSURE INDUCED PHASE TRANSITION AND ELECTRONIC PROPERTIES OF 1D ZnO NANOCRYSTAL: AN AB INITIO STUDY

2012 ◽  
Vol 11 (05) ◽  
pp. 1250035
Author(s):  
ANURAG SRIVASTAVA ◽  
NEHA TYAGI
Keyword(s):  
Density Functional ◽  
Electronic Band Structure ◽  
Electronic Band ◽  
Functional Theory ◽  
Reduced Dimensions ◽  
Zno Nanocrystals ◽  
Zinc Blende ◽  
Type Phase ◽  
The One ◽  
Zno Nanocrystal

We have analyzed the one-dimensional (1D) ZnO nanocrystals in its wurtzite (B4); zinc-blende (B3) and rocksalt (B1) type phases, by means of density functional theory (DFT) calculations. The energetic stability of nanocrystal has been analyzed using Revised Perdew–Burke–Ernzerhof (revPBE) type parameterized GGA potential. The B3 type phase is most stable amongst other phases of nanocrystals. The computation of ground state properties for all the phases of ZnO nanocrystals finds that the bulk modulus are smaller than their bulk counterpart, in turn softening the material at reduced dimensions. The electronic band structure analysis confirms the semiconducting nature of B4 type phase whereas other two are metallic.

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