Scopus İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12416/8651
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Conference Object Citation - WoS: 1Citation - Scopus: 2Effects of Molecular Rovibrational States and Surface Topologies for Molecule-Surface Interaction: Chemisorption Dynamics of D2 Collision With Rigid Ni Surfaces(Sociedade Brasileira de Fisica, 2006) Böyükata, M.; Güvenç, Z.B.A quasiclassical and micro-canonical molecular dynamic simulation techniques have been applied for D2(v, j) + Ni-surface collision systems. Dissociative adsorptions of a D2 molecule on the rigid low index (100), (110) and (111), surfaces of the nickel are investigated to understand the effects of the different surfaces, impact sites and the initial rovibrational states of the molecule on molecule-surface collisions. Interactions between the molecule and the Ni surfaces are mimicked by a LEPS potential. Dissociative chemisorption probabilities of the D2(v, j) Molecule (for the vibrational (v) = 0 and rotational (j) = 0, 1, 3, 10, and for the v = 1, j = 0 states on different impact sites of the surfaces) are presented for the translation energies between 0.001 and 1.0 eV. The probabilities obtained at each collision site have unique behavior for the colliding molecule which is moving along the surface normal direction. It has been observed that at the low collision energies the indirect processes (steering effects) enhance the reactivity on the surfaces. The results are compared to the related studies in the literature.Conference Object Hydrogen Hosting on Aluminum-Doped Boron Clusters: Density Functional Theory(Institute of Physics Publishing, 2009) Böyükata, M.; Güvenç, Z.B.The geometries, stabilities, and energetics of aluminum doped boron clusters, up to 13-atom, and their various hydrogenated complexes have been investigated via the density functional theory (DFT). The geometry optimizations have been carried out by using B3LYP functional and 6-311++G11 basis set. Up to 5-atom clusters arrangements of the atoms, in the most stable structures, have two-dimensional forms. From 6- to 13-atom clusters three-dimensional forms are favored by the lowest energy structures. Hydrogen hosting effects the structures of AlBn clusters. Adding an Al atom to the cage B12 leads structural changes but hydrogenated boron, B12H12 can resist to Al effect. © 2009 IOP Publishing Ltd.Conference Object Citation - WoS: 8Citation - Scopus: 7Quasiclassical Studies of Eley-Rideal and Hot-Atom Reactions on a Surface at 94 K: H(D) → D(H)+cu(Elsevier Science Bv, 2007) Vurdu, C. D.; Oezcelik, S.; Guevenc, Z. B.; Özçelik, S.; Güvenç, Z.B.Reactions and reaction dynamics of gas-phase H(or D) atoms with D(or H) atoms adsorbed onto a Cu(111) surface have been investigated by the quasi-classical molecular dynamics method. To simulate the H(D) -> D(H) + Cu(111) system at a 94 K surface temperature, D(or H) adsorbates were disseminated arbitrarily on the surface of Cu(111) to form 0.50, 0.28 and 0.18 ML of coverages. The interaction of hydrogen atoms and the surface system is worked out by an LEPS function. LEPS parameters have been determined by using the total energy values which were calculated by a density functional theory (DFT) method and the generalized gradient approximation (GGA) for the exchange-correlation energy for various configurations of one and two hydrogen atoms on the Cu(111) surface. The Cu(111) surface, imitated by an embedded-atom method which is a many-body potential parameterized by Voter-Chen, is formed as a multilayer stab. The slab atoms are permitted to move. Various processes, trapping onto the surface, inelastic reflection of the incident projectile and penetration of the adsorbate or projectile atom into the slab, are examined. The dependence of these mechanisms on isotopic replacement has also been analyzed. Considerable contributions of the hot-atom pathways for the product formations are consequently observed. The rate of subsurface penetrations is obtained to be larger than the sticking rate onto the surface. (c) 2007 Elsevier B.V. All rights reserved.