Theoretical Study on Structural and Electronic Properties of EDOT:SS Oligomers Complex

2015 ◽  
Vol 1131 ◽  
pp. 123-127
Author(s):  
Ampaiwan Marutaphan ◽  
Panida Lorwongtragool ◽  
Chatchawal Wongchoosuk
Keyword(s):  
Electronic Properties ◽  
Polymer Chain ◽  
Density Functional ◽  
Theoretical Study ◽  
Energy Gap ◽  
Average Distance ◽  
Geometry Optimization ◽  
Am1 Method ◽  
Structural And Electronic Properties ◽  
Binding Distance

In this paper, we have reported a theoretical study of the geometric and electronic structures of EDOT:SS oligomers based on semi-empirical Austin model1 (AM1) method and density functional theory at B3LYP/3-21G* level. The effects of polymer chain length of both EDOT and SS on structural and electronic properties including bond length, bond angle, binding distance, charge, the highest occupied orbital (HOMO), the lowest unoccupied molecular orbital (LUMO), and energy gap have been studied from the optimized oligomers which were built by varying repeating unit of monomer as n = 1, 2, 3 and 4. The results show that AM1 is not appropriate for geometry optimization of EDOT:SS system comparing to B3LYP/3-21G* level. The binding distance between H atom on EDOT and O atom on SS tends to close together with the average distance of 2.21 Å. The most positive charges locate at sulfur atoms on EDOT and EDOT:SS. The electrical conductivity of EDOT, SS and EDOT:SS increases when polymer chain is extended.

STRUCTURAL AND ELECTRONIC PROPERTIES OF FINITE-LENGTH SINGLE-WALLED CARBON AND SILICON CARBIDE NANOTUBES: DFT STUDY

2013 ◽  
Vol 27 (29) ◽  
pp. 1350210 ◽  
Author(s):  
IGOR K. PETRUSHENKO ◽  
NIKOLAY A. IVANOV
Keyword(s):  
Silicon Carbide ◽  
Electronic Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Basis Set ◽  
Functional Theory ◽  
Single Walled Carbon ◽  
Silicon Carbide Nanotubes ◽  
Structural And Electronic Properties ◽  
Walled Carbon Nanotubes

This paper presents a systematical analysis of the structure and electronic properties of armchair single-walled carbon nanotubes (SWCNTs) as well as single-walled silicon carbide nanotubes ( SiCNTs ) by using density functional theory. The geometries of all species were optimized at the B3LYP level of theory using the SVP basis set. The different behavior of C – C bonds "parallel" and "perpendicular" to the nanotube axis has been found. The HOMO–LUMO energy gap, ionization potential, electron affinity, electronegativity and hardness of studied tubes were compared. The influence of both SWCNTs and SiCNTs lengths on their electronic properties has been analyzed.

FIRST-PRINCIPLES STUDY OF STRUCTURAL AND ELECTRONIC PROPERTIES OF SrLiSb UNDER HIGH PRESSURE

2012 ◽  
Vol 26 (29) ◽  
pp. 1250151
Author(s):  
Z. H. YU ◽  
C. Y. LI ◽  
H. Z. LIU
Keyword(s):  
High Pressure ◽  
Electronic Properties ◽  
First Principles ◽  
Density Functional ◽  
Geometry Optimization ◽  
Generalized Gradient ◽  
Functional Theory ◽  
Generalized Gradient Approximation ◽  
Electronic Phase ◽  
Structural And Electronic Properties

Using the first-principles plane wave pseudopotential method, the structural and electronic properties of intermetallic compound SrLiSb have been studied within generalized gradient approximation in the frame of density functional theory. The calculations of lattice parameters are in well agreement with the available experimental data. The geometry optimization results indicated the compressibility of SrLiSb is anisotropic under high pressure. The energy band structure and density of states of SrLiSb were also calculated, indicating that SrLiSb has an electronic phase transition from direct-gap semiconductor to indirect-gap semiconductor at approximate 8 GPa.

AB INITIO DENSITY FUNCTIONAL THEORY INVESTIGATION OF STRUCTURAL AND ELECTRONIC PROPERTIES OF ZnO BUNDLES

2010 ◽  
Vol 24 (31) ◽  
pp. 2997-3003 ◽  
Author(s):  
ALI FATHALIAN ◽  
ROSTAM MORADIAN ◽  
SHAHDOKHT SOHRABI SANI
Keyword(s):  
Density Functional Theory ◽  
Zinc Oxide ◽  
Ab Initio ◽  
Electronic Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Metallic Behavior ◽  
Functional Theory ◽  
Structural And Electronic Properties ◽  
Nanotube Bundle

By using ab initio density functional theory we investigated the structural and electronic properties of semiconducting (9, 0), zinc oxide zigzag nanotube ( ZnOZNT ) bundle. The energetic and electronic evolutions of nanotubes in the bundling process are also studied. The effects of inter-tube coupling on the electronic dispersions of ZnONT bundle are demonstrated. Our results show that the inter-tube coupling leads to disappearance of the energy gap in semiconducting nanotube. We found that (9, 0) zigzag nanotube bundle has a metallic behavior.

scholarly journals Structural and Electronic Properties of Qatranaite

2019 ◽  
Vol 2019 ◽  
pp. 1-6
Author(s):  
Anna Majtyka-Piłat ◽  
Dariusz Chrobak ◽  
Roman Nowak ◽  
Marcin Wojtyniak ◽  
Mateusz Dulski ◽  
...  
Keyword(s):  
Band Gap ◽  
Electronic Properties ◽  
Density Functional ◽  
Energy Gap ◽  
Local Density ◽  
Functional Theory ◽  
Structure Relaxation ◽  
Structural And Electronic Properties ◽  
Gap Width ◽  
Band Gap Width

The present work addresses the atomic structure and electronic properties of a recently discovered mineral qatranaite (CaZn2(OH)6·2H2O). The present study was performed theoretically by means of density functional theory- (DFT-) based calculations within the frame of local density approximation (LDA) and general gradient approximation (GGA). To determine the energy band gap width, we carried out the ultraviolet-visible spectroscopy (UV-Vis) measurements. The structure relaxation performed with use of LDA and GGA provides results matching the experimentally determined crystal parameters. Interestingly, in contrast to existing interpretation of experimental data, our DFT calculations revealed energy gap of direct characteristics. Accordingly, our UV-Vis experiments yield the band gap width of 3.9 eV.

Structural and Electronic Properties of Ag-Doped in Ba-Site of YBa2-xAgxCu3Oδ Using Density Functional Theory via First Principle Study

2021 ◽  
Vol 317 ◽  
pp. 549-555
Author(s):  
Siti Fatimah Saipuddin ◽  
Mohamad Syafie Mahmood ◽  
Azhan Hashim ◽  
Nurbaisyatul Ermiza Suhaimi ◽  
Mohamad Fariz Mohamad Taib
Keyword(s):  
Density Functional Theory ◽  
Electronic Properties ◽  
Density Functional ◽  
Structural Changes ◽  
Local Density ◽  
Geometry Optimization ◽  
Computational Method ◽  
First Principle ◽  
Functional Theory ◽  
Structural And Electronic Properties

This study reports on the First Principle Study via Density Functional Theory (DFT) used to determine the structural and electronic properties of Ag-dopant in Ba-site of YBa2-xAgxCu3Oδ superconductor. The computational method adopting CASTEP computational code was used to calculate the structural and electronic properties for Ag-dopant in range of x=0.150 to x=0.250 in Ba-site of YBa2-xAgxCu3Oδ to enhance the performance finding of experimental work shown at dopant x=0.20 ceramic superconductor. The structural changes in terms of lattice parameters were compared as the percentage of dopant increases to seek both CuO chain and CuO2 plane bond length and the spontaneous strain variance on the structure orthorhombicity. The crystal structure constructed and calculated using Visual Crystal Approximation (VCA) applying the local density approximation (LDA) and ultrasoft pseuodopotential. Geometry optimization shown energy converged at 400 eV with k-point sampling of 4x4x1. The structural properties of YBa2-xAgxCu3Oδ are observed to be approximately close to the experimental data obtained by other researches. The electronic properties were determined via energy band gap, density of states and electron energy differences visualisation a to further enhance the experimental findings.

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