Browsing by Keywords "Density functional theory"
Now showing items 1-20 of 53
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Ab initio study of hydrogenic effective mass impurities in Si nanowires
(Institute of Physics Publishing, 2017-01)The effect of B and P dopants on the band structure of Si nanowires is studied using electronic structure calculations based on density functional theory. At low concentrations a dispersionless band is formed, clearly ... -
Ab initio temperature dependent studies of the homoepitaxial growth on Si(0 0 1) surface
(2001)We performed ab initio zero temperature and finite temperature molecular dynamics calculations to investigate the homoepitaxial growth on the Si(0 0 1) surface. How do the deposited atoms (adatoms) form addimers and how ... -
Anatase TiO2 nanowires functionalized by organic sensitizers for solar cells: a screened Coulomb hybrid density functional study
(American Institute of Physics Inc., 2015)The adsorption of two different organic molecules cyanidin glucoside (C21O11H20) and TA-St-CA on anatase (101) and (001) nanowires has been investigated using the standard and the range separated hybrid density functional ... -
Band Structure and Optical Properties of Kesterite Type Compounds: First principle calculations
(Institute of Physics Publishing, 2017)In present work, our research is mainly focused on the electronic structures, optical and magnetic properties of Cu2FeSnZ4 (Z = S, Se) compounds by using ab initio calculations within the generalized gradient approximation ... -
Bell solitons in ultra-cold atomic Fermi gas
(2013)We demonstrate the existence of supersonic bell solitons in the Bardeen-Cooper-Schrieffer-Bose-Einstein condensate crossover regime. Starting from the extended Thomas-Fermi density functional theory of superfluid order ... -
Bias in bonding behavior among boron, carbon, and nitrogen atoms in ion implanted a-BN, a-BC, and diamond like carbon films
(2011)In this study, we implanted Nþ and Nþ 2 ions into sputter deposited amorphous boron carbide (a-BC) and diamond like carbon (DLC) thin films in an effort to understand the chemical bonding involved and investigate possible ... -
Characterization of platinum nitride from first-principles calculations
(Institute of Physics Publishing, 2009)We have performed a systematic study of the ground state properties of the zinc-blende, rock-salt, tetragonal, cuprite, fluorite and pyrite phases of platinum nitride by using the plane wave pseudopotential calculations ... -
Chemically uracil-functionalized carbon and silicon carbide nanotubes: computational studies
(Elsevier, 2018)Chemical additions of uracil (U) nucleobase to sidewall of each of representative (4,4) armchair carbon and silicon carbide nanotubes (CNT and SiCNT) were investigated based on density functional theory (DFT) calculations. ... -
Comparative analysis of reactant and product adsorption energies in the selective oxidative coupling of alcohols to esters on Au (111)
(Springer, 2016)Gold-based heterogeneous catalysts have attracted significant attention due to their selective partial oxidation capabilities, providing promising alternatives for the traditional industrial homogeneous catalysts. In the ... -
A desity functional study on narrow band gap donor-acceptor type conducting polymers
(Bilkent University, 2004)The band gap is one of the most important factors for controlling the physical properties. The search for polymers having narrow band gaps is a current topic. Tuning of the band gap by structural modification is possible. ... -
DFT explorations of quadrupole coupling constants for planar 5-fluorouracil pairs
(Elsevier, 2016-08)Atomic scale properties of quadrupole coupling constants (CQ) have been evaluated for singular and paired 5-fluorouracil (FU) models. Structural possibilities and properties for various types of hydrogen bonded (HB) homo ... -
DFT studies of CNT-functionalized uracil-acetate hybrids
(Elsevier, 2015)Calculations based on density functional theory (DFT) have been performed to investigate the stabilities and properties of hybrid structures consisting of a molecular carbon nanotube (CNT) and uracil acetate (UA) counterparts. ... -
Dipeptide adsorption on Si (100)-2x1 asymmetric surface by first principles
(World Scientific Publishing Co. Pte. Ltd, 2010)The adsorption of alanine dipeptide on a Si(100)-2 × 1 asymmetric surface is studied by using pseudopotential plane wave approach based on Density Functional Theory (DFT). Adsorption energies for different surface sites ... -
Dynamic nonlinear optical processes in some oxygen-octahedra ferroelectrics: first principle calculations
(Taylor & Francis Inc., 2015)The nonlinear optical properties and electro-optic effects of some oxygen-octahedra ferroelectrics are studied by the density functional theory (DFT) in the local density approximation (LDA) expressions based on first ... -
Effect of chalcogens on electronic and photophysical properties of vinylene-based diketopyrrolopyrrole copolymers
(American Chemical Society, 2015)Three vinylene linked diketopyrrolopyrrole based donor−acceptor (D−A) copolymers have been synthesized with phenyl, thienyl, and selenyl units as donors. Optical and electronic properties were investigated with UV−vis ... -
Effect of disorder on the interacting fermi gases in a one-dimensional optical lattice
(World Scientific Publishing Co., 2008)Interacting two-component Fermi gases loaded in a one-dimensional (1D) lattice and subjected to a harmonic trapping potential exhibit interesting compound phases in which fluid regions coexist with local Mott-insulator ... -
Effects of perfluorination on thiophene and pyrrole oligomers
(2010)The effect of perfluorination on thiophene and pyrrole oligomers in neutral, cationic, and anionic states was investigated with density functional theory at the (TD)B3P86-30%/6-31G* level. For the title compounds fluorination ... -
Electron spectroscopy and the electronic structure of KNbO3: First principle calculations
(Taylor & Francis Online, 2014)The electronic structures of KNbO3were calculated within the density functional theory, and their evolution was analyzed as the crystal-field symmetry changes from cubic to rhombohedral via tetragonal phase. We carried out ... -
Electronic and optical properties of 4.2 μm"N" structured superlattice MWIR photodetectors
(Elsevier, 2013)We report on the development of a new structure for type II superlattice photodiodes that we call the "N" design. In this new design, we insert an electron barrier between InAs and GaSb in the growth direction. The barrier ... -
Electronic structure analysis of a new quinoid conjugated polymer
(Springer, 2000)The low lying unoccupied orbitals of oligomers of 4-dicyanomethylene-4H-cyclopenta[2,1-b:3,4-b'] dithiophene (CDM) are not delocalized over the whole molecule. Is such electron localization in the conduction band of poly-CDM ...
