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.

FIRST-PRINCIPLES STUDIES ON THE ELECTRONIC STRUCTURE OF BaCuSi2O6

2010 ◽  
Vol 24 (14) ◽  
pp. 2205-2210
Author(s):  
T. JEONG
Keyword(s):  
Electronic Structure ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Structure Calculation ◽  
Band Structure Calculation ◽  
Density Approximation ◽  
Structure And Properties ◽  
Functional Theory ◽  
The Density Functional Theory

The electronic properties of BaCuSi 2 O 6 are studied by band structure calculation based on the density functional theory within local density approximation. We find that the electronic structure and properties are dominated by the layered character of the crystal structure arising from the in plane Cu 3d and O 2p electron interactions.

Thermodynamic properties of ZnTe in zinc-blende and wurtzite phases

2016 ◽  
Vol 30 (21) ◽  
pp. 1650147 ◽  
Author(s):  
S. Ferahtia ◽  
S. Saib ◽  
N. Bouarissa
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Density Approximation ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Zinc Blende ◽  
The Density Functional Theory ◽  
Two Phases

The present study deals with first-principles calculations of the thermal properties of ZnTe in the two phases namely, zinc-blende and wurtzite. The calculations are mainly performed using the density functional theory with the local density approximation and response-function calculations. The full phonon dispersions throughout the Brillouin zone are presented. The temperature dependence of the lattice parameters, bulk modulus, entropy and heat capacity are examined and discussed. Our findings agree reasonably well with those available in the literature.

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.

First-principles Calculations of Energetic Properties of Vacancies, Mn-atomic Defects in CdTe

2006 ◽  
Vol 959 ◽  
Author(s):  
Ghouti Merad ◽  
Benali Rerbal ◽  
Hafid Aourag ◽  
Joël Cibert
Keyword(s):  
Density Functional Theory ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Density Approximation ◽  
First Principles Calculations ◽  
Functional Theory ◽  
Energetic Properties ◽  
Atomistic Modelling ◽  
Atomic Type

ABSTRACTAn atomistic modelling based on density functional theory within the framework of the local density approximation is used to show the trends in the energetic properties of single and double defects in CdTe semiconductor, without phase transformation. A systematic study of vacancies, Mn substituting Cd atoms in a supercell structure consisting of 16-atoms is presented. The changes of structural properties and lattice parameters due to the addition of Mn-atomic type defects in CdTe matrix are compared, and the number of vacancies is also determined from the total energy calculations.

ELECTRONIC AND DYNAMICAL PROPERTIES OF MgB2 AND RELATED COMPOUNDS

2002 ◽  
Vol 16 (11n12) ◽  
pp. 1563-1569 ◽  
Author(s):  
G. PROFETA ◽  
A. CONTINENZA ◽  
F. BERNARDINI ◽  
G. SATTA ◽  
S. MASSIDDA
Keyword(s):  
Density Functional Theory ◽  
Local Density Approximation ◽  
Density Functional ◽  
Local Density ◽  
Density Approximation ◽  
Superconducting Properties ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Dynamical Properties ◽  
Related Compounds

We report a detailed study of the electronic and dynamical properties of MgB2 , BeB2 and of the AlMgB4 superlattice, within the local density approximation to the density functional theory. On the basis of our results we discuss the superconducting properties of these systems, and point to the high T c in MgB2 as a fortunate combination of events.

OPTICAL SPIN INJECTION IN SEMICONDUCTORS

2010 ◽  
Vol 24 (14) ◽  
pp. 1507-1522
Author(s):  
BERNARDO S. MENDOZA ◽  
CUAUHTÉMOC SALAZAR ◽  
J. L. CABELLOS
Keyword(s):  
Density Functional Theory ◽  
Local Density Approximation ◽  
Density Functional ◽  
Local Density ◽  
Spin Injection ◽  
Density Approximation ◽  
Functional Theory ◽  
Electronic Wavefunctions ◽  
The Density Functional Theory ◽  
Bulk Semiconductors

A theoretical review of optical spin injection for bulk semiconductors is presented. As an example, we calculated such response in bulk Si , GaAs and CdSe . For each of these systems the computation of the electronic wavefunctions and energies are obtained under the density functional theory (DFT) within the local density approximation (LDA).

First-principles study of electronic and optical properties of solid-solution ZnO1−xSx

2017 ◽  
Vol 31 (23) ◽  
pp. 1750175 ◽  
Author(s):  
Margi Jani ◽  
Abhijit Ray
Keyword(s):  
Solid Solution ◽  
Density Functional Theory ◽  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Local Density ◽  
Density Approximation ◽  
Functional Theory ◽  
Electronic And Optical Properties ◽  
Strong Localization

We investigated the electronic and optical properties of ZnO under the circumstances of isovalent anionic doping by sulfur. A pseudopotential implementation of density functional theory is applied within the local density approximation to examine the modification of band structure in wurtzite ZnO by sulfur substitution. Although Fermi level position does not change, a strong localization of Zn-[Formula: see text] orbital is found by S-doping. Optical properties and constants are found to strongly depend on the sulfur content at low photon energies.

ON THE "GENERALIZED SLATER" APPROXIMATION

2009 ◽  
Vol 23 (20n21) ◽  
pp. 4087-4095
Author(s):  
J. MESSUD ◽  
P. M. DINH ◽  
E. SURAUD ◽  
P.-G. REINHARD
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Local Density ◽  
Local Approximation ◽  
Approximate Theory ◽  
Density Approximation ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Non Local ◽  
Best Local Approximation

We work within the Density Functional Theory (DFT), in the Local Density Approximation (LDA) with Self Interaction Correction (SIC). We show that, thanks to a formulation which employs two different sets of orbitals, the equations can be written in the form of eigenvalues equations, leading to single electron interpretation. However, the resulting hamiltonian is non-local. We propose to find it's best local approximation within using the Optimized Effective Potential (OEP) method. The resulting approximate theory is denominated "Generalized Slater". We show that this new scheme cures the pathologies of the standard SIC-Slater or SIC-KLI approximations.

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