Microcrystalline β-RbNd(MoO4)2: spin polarizing DFT+U

RSC Advances ◽  
2015 ◽  
Vol 5 (56) ◽  
pp. 44960-44968 ◽  
Author(s):  
A. H. Reshak
Keyword(s):  
Density Functional ◽  
Electronic Band Structure ◽  
Electronic Charge ◽  
Charge Density Distribution ◽  
Electronic Charge Density ◽  
Electronic Band ◽  
Functional Theory ◽  
Hubbard Hamiltonian ◽  
The Density Functional Theory ◽  
Structure Density

Using the density functional theory plus Hubbard Hamiltonian we have investigated the spin up/down electronic band structure, density of states, electronic charge density distribution and the dispersion of the optical properties of microcrystalline β-RbNd(MoO4)2.

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.

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 Effect on the Electronic Properties of Cerium Monochalcogenides CeX (X=S, Se, Te) Using Modified Becke-Johnson Exchange Potential and LDA+U

2014 ◽  
Vol 925 ◽  
pp. 390-395
Author(s):  
Noureddine Amrane ◽  
Maamar Benkraouda
Keyword(s):  
Electronic Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Exchange Potential ◽  
Full Potential ◽  
Electronic Band ◽  
Functional Theory ◽  
Augmented Plane Wave ◽  
The Density Functional Theory ◽  
Linearized Augmented Plane Wave

We present a systematic and comparative study of the electronic properties of CeX monochalcogenides, The density of state (DOS) and electronic band structure of CeX (X=S, Se, Te) have been calculated using the full-potential linearized augmented plane-wave (FP-LAPW) + local orbital (lo) method based on the density functional theory (DFT), which is implemented in WIEN2k code. The trends in the high pressure behavior of these systems are discussed. Four approximations for the exchange-correlation functional have been used, the GGA's of Perdew-Burke-Ernzherhof. (PBE08) , Engel-Vosko (EV93), a modified version of the exchange potential proposed by Becke and Johnson (MBJ), and LDA+U is used to calculate the band gaps at different pressures. All methods allow for a description of the Ce f electrons as either localized or delocalized, it is found that the underestimations of the bandgap by means of LDA-GGA and Engel-Vosko are considerably improved by using the modified Becke-Johnson (MBJ) potential for all compounds in the series, On the other hand, LDA+U, method gives good results for the lighter chalcogenides, but it fails to give good results for the heavier cerium monochalcogenides.

Ab initioMolecular and Solid State Studies of the FeII Spin Cross-over System [Fe(btz)2(NCS)2] (btz = 2.2’-bis-4.5-dihydrothiazine)

2008 ◽  
Vol 63 (2) ◽  
pp. 154-160 ◽  
Author(s):  
Lara Kabalan ◽  
Samir F. Matar ◽  
Mirvat Zakhour ◽  
Jean François Létarda
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Crystalline Solid ◽  
Infrared And Raman Spectra ◽  
Full Account ◽  
Electronic Band ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Structure Properties

Ab initio computations within the density functional theory are reported for the spin cross-over complex [Fe(btz)2(NCS)2] (btz = 2.2'-bis-4.5-dihydrothiazine), where 3d6 FeII is characterized by high-spin (HS t2g4, eg2) and low-spin (LS t2g6, eg0) states. Results of infrared and Raman spectra for the isolated molecule are complemented for the crystalline solid with a full account of the electronic band structure properties: the density of states assessing the crystal field effects and the chemical bonding, assigning a specific role to the Fe-N interactions within the coordination sphere of FeII

scholarly journals Elastic and optical properties of sillenites: First principle calculations

2020 ◽  
Vol 557 (1) ◽  
pp. 98-104 ◽  
Author(s):  
Husnu Koc ◽  
Selami Palaz ◽  
Sevket Simsek ◽  
Amirullah M. Mamedov ◽  
Ekmel Ozbay
Keyword(s):  
Optical Properties ◽  
Electronic Structures ◽  
Density Functional ◽  
Electronic Band Structure ◽  
First Principle ◽  
Electronic Band ◽  
Functional Theory ◽  
First Principle Calculations ◽  
Optical Functions ◽  
The Density Functional Theory

In the present paper, we have investigated the electronic structure of some sillenites - Bi12MO20 (M = Ti, Ge, and Si) compounds based on the density functional theory. The mechanical and optical properties of Bi12MO20 have also been computed. The second-order elastic constants have been calculated, and the other related quantities have also been estimated in the present work. The band gap trend in Bi12MO20 can be understood from the nature of their electronic structures. The obtained electronic band structure for all Bi12MO20 compounds is semiconductor in nature. Similar to other oxides, there is a pronounced hybridization of electronic states between M-site cations and anions in Bi12MO20. Based on the obtained electronic structures, we further calculate the frequency-dependent dielectric function and other optical functions.

scholarly journals Влияние размерных эффектов на электронную структуру гексагонального теллурида галлия

2018 ◽  
Vol 60 (9) ◽  
pp. 1645
Author(s):  
А.В. Кособуцкий ◽  
С.Ю. Саркисов
Keyword(s):  
Density Functional ◽  
Electronic Band Structure ◽  
Bulk Material ◽  
Structural Parameters ◽  
Van Der Waals Interactions ◽  
Electronic Band ◽  
Functional Theory ◽  
Lower Conduction Band ◽  
The Density Functional Theory ◽  
Indirect Band Gap

AbstractUsing methods of the density functional theory, the electronic band structure of a hexagonal modification of the layered GaTe semiconductor has been calculated. The structural parameters of a bulk crystal with the β-polytype symmetry have been determined taking into account van der Waals interactions and agree with experimental data for polycrystalline films within 2%. Estimates for the position of extrema of the upper valence band and the lower conduction band have been obtained with respect to the vacuum level for bulk β-GaTe and for ultrathin plates with the number of elementary layers ranging from 1 to 10, which corresponds to a thickness range of 0.5–8 nm. The calculations demonstrate that hexagonal GaTe is an indirect band gap semiconductor with a forbidden band width varying from 0.8 eV in the bulk material to 2.3 eV in the monolayer.

Firs-Principles Investigation of the Electronic and Optical Properties of B-Doped ZnO under Pressure

2019 ◽  
Vol 807 ◽  
pp. 115-120
Author(s):  
Ling Ping Xiao ◽  
Yun Qin Liu
Keyword(s):  
Density Functional Theory ◽  
High Pressure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Pressure Effects ◽  
Partial Density ◽  
Electronic Band ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Doped Zno

Based on the density functional theory (DFT), the first-principles approach is used to study the electronic band structure of B-doped wuritzite ZnO with different pressure. The pressure effects on the lattice parameters, electronic band structures, and partial density of states (PDOS) of crystalline B-doped ZnO are calculated up to 8 GPa. Moreover, the evolution of the dielectric function, absorption coefficient (), reflectivity (), and the real part of the refractive index () at high pressure are also presented. Keywords: high pressure; density functional theory; B-doped ZnO.

Modulation of the electronic band structure of silicene by polar two-dimensional substrates

2020 ◽  
Vol 22 (37) ◽  
pp. 21412-21420 ◽  
Author(s):  
KaiJuan Pang ◽  
YaDong Wei ◽  
Xiaodong Xu ◽  
WeiQi Li ◽  
JianQun Yang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Two Dimensional ◽  
Electronic Band ◽  
Functional Theory ◽  
Electron Band ◽  
Group Iii ◽  
The Density Functional Theory ◽  
Dirac Electron

Using the density functional theory (DFT) calculations, we find that group-III chalcogenide monolayers can serve as a suitable substrate for silicene, and the Dirac electron band properties of silicene are also fully preserved.

scholarly journals Электронная структура, оптические свойства и поведение под давлением в соединениях CdB-=SUB=-4-=/SUB=-O-=SUB=-7-=/SUB=- и HgB-=SUB=-4-=/SUB=-O-=SUB=-7-=/SUB=-

2018 ◽  
Vol 60 (9) ◽  
pp. 1662
Author(s):  
А.С. Шинкоренко ◽  
В.И. Зиненко ◽  
М.С. Павловский
Keyword(s):  
Phase Transition ◽  
Density Functional Theory ◽  
Optical Properties ◽  
Band Structure ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Electronic Band ◽  
Functional Theory ◽  
Structural Modifications ◽  
The Density Functional Theory

AbstractAb initio calculations of the structural, electronic, and optical properties of the CdB_4O_7 and HgB_4O_7 tetraborate compounds in three structural modifications with the Pbca , Cmcm , and Pmn 2_1 symmetry have been performed in the framework of the density functional theory using the VASP package. The calculations of the electronic band structure showed that these compounds in all the investigated modifications are dielectrics with a band gap of 2–4 eV. The calculation of the structural properties of the tetraborates under pressure showed that the phase transition between the Pbca and Pmn 2_1 structures in cadmium and mercury tetraborates occurs under pressures of 4.8 and 4.7 GPa, respectively.

scholarly journals Influence of uniaxial stresses on electronic and optical properties of β-K2SO4 crystal

2015 ◽  
Vol 33 (1) ◽  
pp. 11-17 ◽  
Author(s):  
B. Andriyevsky ◽  
M. Jaskólski ◽  
V.Y. Stadnyk ◽  
M.O. Romanyuk ◽  
Z.O. Kashuba ◽  
...  
Keyword(s):  
Optical Properties ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Uniaxial Stress ◽  
Electronic Band ◽  
Practical Applications ◽  
Optical Sensitivity ◽  
Stress Sensors ◽  
The Density Functional Theory ◽  
Structure Density

AbstractIn view of possible practical applications of transparent crystals for mechanical stress sensors, theoretical investigation of piezo(elasto)optic effect in crystals might be useful for searching for proper materials, possessing large coefficients of elasto-optic effect, and for determination of uniaxial stress directions of maximum piezo-optical sensitivity. The influence of the uniaxial stresses on the electronic band structure, density of states, and optical properties of potassium sulphate crystal β-K2SO4 have been studied in the framework of the density functional theory using the ab initio CASTEP code. Increase in the band gap, Eg of the crystal takes place for three crystallographic directions and for moderate uniaxial stresses, σ < 1.5 GPa. Dependencies of principal refractive indices and polarizabilities upon principal uniaxial stresses are discussed together with other features of electronic structure of the crystal.

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