Browsing by Author "Gülseren, O."
Now showing items 1-20 of 54
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Ab initio study of neutral ( TiO2 ) n clusters and their interactions with water and transition metal atoms
Çakır, D.; Gülseren, O. (IOP Publishing, 2012-07-04)We have systematically investigated the growth behavior and stability of small stoichiometric (TiO2)n (n = 1–10) clusters as well as their structural, electronic and magnetic properties by using the first-principles plane ... -
Adsorption of Pt and Bimetallic Pt-Au clusters on the partially reduced rutile (110) TiO2 surface: a first-principles study
Çakır, D.; Gülseren, O. (American Chemical Society, 2012)An extensive study of the adsorption of small Ptn (n = 1−8) and bimetallic Pt2Aum (m = 1−5) clusters on the partially reduced rutile (110) TiO2 surface has been nperformed via total energy pseudopotential calculations based ... -
Anatase TiO2 nanowires functionalized by organic sensitizers for solar cells: a screened Coulomb hybrid density functional study
Ünal, H.; Gunceler, D.; Gülseren, O.; Ellialtıoğlu, S.; Mete, E. (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 ... -
Characterization of platinum nitride from first-principles calculations
Yıldız, A.; Akıncı, Ü.; Gülseren, O.; Sökmen, İ. (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 ... -
A comparative study of O2 adsorbed carbon nanotubes
Dag, S.; Gülseren, O.; Çıracı, Salim (2003)First-principles, density functional calculations show that O2 adsorbed single-wall carbon nanotubes (SWNT) show dramatic differences depending on the type of the tube. Upon O2 physisorption, the zig-zag SWNT remains ... -
DFT explorations of quadrupole coupling constants for planar 5-fluorouracil pairs
Mirzaei, M.; Gülseren, O.; Hadipour, N. (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 graphene-functionalised derivatives of capecitabine
Aramideh, M.; Mirzaei, M.; Khodarahmi, G.; Gülseren, O. (Walter de Gruyter GmbH, 2017-10)Cancer is one of the major problems for so many people around the world; therefore, dedicating efforts to explore efficient therapeutic methodologies is very important for researchers of life sciences. In this case, ... -
DFT study of noble metal impurities of TiO2 ( 110 )
Mete, E.; Gülseren, O.; Ellialtıoğlu, Ş. (Springer Verlag, 2012-06)Atomic and electronic structures of TiO2(110) surface with possible adsorptional, substitutional and interstitial Au or Pt elemental impurities at full and one-sixth monolayer concentrations were investigated by density ... -
Dipeptide adsorption on Si (100)-2x1 asymmetric surface by first principles
Aktürk, E.; Gülseren, O.; Arkin, H.; Çelik, T. (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 ... -
Dye adsorbates BrPDI, BrGly, and BrAsp on anatase TiO2 (001) for dye-sensitized solar cell applications
Çakır, D.; Gülseren, O.; Mete, E.; Ellialtıoǧlu, Ş. (American Physical Society, 2009)Using the first-principles plane-wave pseudopotential method within density functional theory, we systematically investigated the interaction of perylenediimide PDI-based dye compounds BrPDI, BrGly, and BrAsp with both ... -
Effect of impurities on the mechanical and electronic properties of Au, Ag, and Cu monatomic chain nanowires
Çakır, D.; Gülseren, O. (American Physical Society, 2011)In this study, we have investigated the interaction of various different atomic and molecular species (H, C, O, H 2, and O 2) with the monatomic chains of Au, Ag, and Cu via total-energy calculations using the plane-wave ... -
Effects of hydrogen adsorption on single-wall carbon nanotubes: metallic hydrogen decoration
Gülseren, O.; Yildirim, T.; Çıracı, Salim (American Physical Society, 2002)We show that the electronic and atomic structure of carbon nanotubes undergo dramatic changes with hydrogen chemisorption from first principle calculations. Upon uniform exohydrogenation at half coverage, the cross sections ... -
Electric-field effects on finite-length superlattices
Gülseren, O.; Çıracı, Salim (1992)In this paper, we study the Wannier-Stark ladder by carrying out numerical calculations on a multiple-quantum-well structure under an applied electric field. The variation in the Wannier-Stark-ladder energies and the degree ... -
Electronic structure of half-metallic ferromagnet Co2MnSi at high-pressure
Gökoǧlu, G.; Gülseren, O. (Springer New York LLC, 2010)In this study, first principles calculation results of the half-metallic ferromagnetic Heusler compound Co2MnSi are presented. All calculations are based on the spin-polarized generalized gradient approximation (σ-GGA) of ... -
Electronic structure of strained Sin / Gen (001) superlattices
Çıracı, Salim; Gülseren, O.; Ellialtioğlu, Ş. (Pergamon Press, 1988)Using the empirical tight binding method we have investigated the electronic properties of the Sin/Gen(001) strained superlattices as a function of the superlattice periodicity and the band misfit. For n ≥ 4 we have found ... -
Electronic structure of the contact between carbon nanotube and metal electrodes
Dag, S.; Gülseren, O.; Çıracı, Salim; Yildirim, T. (American Institute of Physics, 2003)Our first-principles study of the contact between a semiconducting single-walled carbon nanotube ~s-SWNT! and metal electrodes shows that the electronic structure and potential depend strongly on the type of metal. The ... -
Electronic structures and optical spectra of thin anatase TiO2 nanowires through hybrid density functional and quasiparticle calculations
Ünal, H.; Gülseren, O.; Ellialtıoğlu, Ş.; Mete, E. (American Physical Society, 2014)The electronic properties of quasi-one-dimensional anatase TiO2 nanostructures, in the form of thin nanowires having (101) and (001) facets, have been systematically investigated using the standard, hybrid density functional ... -
Energetics and Electronic Structures of Individual Atoms Adsorbed on Carbon Nanotubes
Durgun, Engin; Dag, S.; Çıracı, Salim; Gülseren, O. (American Chemical Society, 2004)The adsorption of individual atoms on the semiconducting and metallic single-walled carbon nanotubes (SWNT) has been investigated by using the first principles pseudopotential plane wave method within density functional ... -
Exohydrogenated single-wall carbon nanotubes
Yildirim, T.; Gülseren, O.; Çıracı, Salim (American Physical Society, 2001)An extensive first-principles study of fully exohydrogenated zigzag (n,0) and armchair (n,n) single-wall carbon nanotubes (CnHn), polyhedral molecules including cubane, dodecahedrane, and C60H60 points to crucial differences ... -
First principles study of electronic and mechanical properties of molybdenum selenide type nanowires
Çakir, D.; Durgun, Engin; Gülseren, O.; Çıracı, Salim (American Physical Society, 2006)Using the first-principles plane-wave pseudopotential method within density functional theory, we have systematically investigated structural, electronic, and mechanical properties of M2 Y6 X6, Y6 X6 (X=Se,Te,S; Y=Mo,Cr,W; ...