First-principles calculation of the AlAs/GaAs interface band structure using a self-energy–corrected local density approximation

2011 ◽  
Vol 94 (2) ◽  
pp. 27001 ◽  
Author(s):  
M. Ribeiro ◽  
L. R. C. Fonseca ◽  
L. G. Ferreira
Keyword(s):  
Band Structure ◽  
First Principles ◽  
Local Density Approximation ◽  
Local Density ◽  
First Principles Calculation ◽  
Density Approximation ◽  
Self Energy

THE PROBLEM OF THE BAND GAP IN LDA CALCULATIONS

2007 ◽  
Vol 14 (03) ◽  
pp. 481-487 ◽  
Author(s):  
I. N. YAKOVKIN ◽  
P. A. DOWBEN
Keyword(s):  
Density Functional Theory ◽  
Band Structure ◽  
Band Gap ◽  
Local Density Approximation ◽  
Density Functional ◽  
Local Density ◽  
Fine Tuning ◽  
Density Approximation ◽  
Functional Theory ◽  
Basic Physics

In calculating band structure, the local density approximation and density functional theory are widely popular and do reproduce a lot of the basic physics. Regrettably, without some fine tuning, the local density approximation and density functional theory do not generally get the details of the experimental band structure correct, in particular the band gap in semiconductors and insulators is generally found to be too small when compared with experiment. For experimentalists using commercial packages to calculate the electronic structure of materials, some caution is indicated, as some long-standing problems exist with the local density approximation and density functional theory.

FIRST PRINCIPLES CALCULATION OF THE ELECTRONIC AND STRUCTURAL PROPERTIES OF USn3 USING LDA+U METHOD

2005 ◽  
Vol 19 (18) ◽  
pp. 3049-3061 ◽  
Author(s):  
A. POURGHAZI ◽  
Z. NOURBAKHSH
Keyword(s):  
Electric Field ◽  
Electric Field Gradient ◽  
Field Gradient ◽  
Local Density Approximation ◽  
Local Density ◽  
Coulomb Repulsion ◽  
First Principles Calculation ◽  
Normal Density ◽  
Density Approximation ◽  
Electronic Band

The actinide compounds exhibit a variety of unusual ground states. These states are dominated by the strong electron-electron correlations that are not included in normal density-functional electronic band-structure calculation with the local density approximation. These correlations are taken into account in the local density approximation +U (LDA+U) method. We have calculated the Coulomb repulsion term U for uranium in USn 3 compound, and investigated the total and partial DOS for USn 3 using LDA+U method. The LDA+U results for USn 3 have been compared with similar results from a ThSn 3 model calculation through which the number of 5f electrons outside the U muffin-tin sphere in USn 3 has been deduced. We have also calculated the electric field gradient (EFG), which may be regarded as a measure of the asymmetry in charge distribution, at the Sn site in USn 3 in LDA , LDA+SO and LDA+SO+U methods, and have shown that the Coulomb repulsion term does not introduce any considerable effect on the electric field gradient at the Sn site.

Possible Ferroelectricity in SnTiO3 by First-Principles Calculations

2002 ◽  
Vol 748 ◽  
Author(s):  
Yoshinori Konishi ◽  
Michio Ohsawa ◽  
Yoshiyuki Yonezawa ◽  
Yoshiya Tanimura ◽  
Toyohiro Chikyow ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Spontaneous Polarization ◽  
First Principles ◽  
Local Density Approximation ◽  
Lattice Structure ◽  
Local Density ◽  
Density Approximation ◽  
First Principles Calculations ◽  
Minimum Total Energy ◽  
The Moment

ABSTRACTThe prospect of lattice structure and ferroelectricity of SnTiO3 have been studied by first-principles calculations within local density approximation. The results showed that the SnTiO3 has the minimum total energy within almost tetragonal perovskite structure of a=b=3.80 Å, c=4.09 Å. The calculated electronic structure of SnTiO3 resembles that of PbTiO3 because the Ti 3d states, Sn 5s and 5p states hybridize with the O 2p orbitals. The moment of spontaneous polarization of SnTiO3 was estimated as 73 μ C/cm2, which is as large as that of PbTiO3.

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.

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