Mustafa Böyükata

Reactions of small Ni clusters with a diatomic molecule : MD simulation of D2 + Nin (n = 7-10) systems

The kinetics of the reactions of nickel clusters with a deuterium molecule are studied. Dissociative chemisorption probabilities of the D{sub 2} molecule on the small Ni{sub n} (n=7-10) clusters are computed by a quasi-classical molecular dynamics computer simulation technique. Structures of the clusters are obtained by an embedded-atom potential, and the interaction between the D{sub 2} and Ni{sub n} is modelled by an LEPS (London-Eyring-Polanyi-Sato) function (energy surface). This analysis includes the chemisorption probabilities as functions of the impact parameter and of the relative translational energy of the D{sub 2}. The corresponding reactive cross-sections for the ground state of the molecule are calculated as functions of the collision energy and the size of the cluster. The role of the size of the clusters is examined. An indirect mechanism to the reaction, which involves formation of molecular adsorption as precursors to dissociative adsorption in the low collision energy region (less than 0.1 eV), is observed. Results are discussed by comparing with the other similar theoretical and experimental studies.

Estimation of cross sections for molecule-cluster interactions by using artificial neural networks

The cross sections of D2(v,j)+Nin(T), n = 19 and 20, collision systems have been estimated by using Artificial Neural Networks (ANNs). For training, previously determined cross section values via molecular dynamics simulation have been used. The performance of the ANNs for predicting any quantities in molecule-cluster interaction has been investigated. Effects of the temperature of the clusters and the rovibrational states of the molecule are analyzed. The results are in good agreement with previous studies.

Hydrogen hosting on aluminum-doped boron clusters: Density functional theory

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.

D2 +Nin(T), n=7 and 9, Collision System

In this study the kinetics of reactions of Nin n=7 and 9, clusters with a deuterium D2 molecule are studied via quasiclassical molecular dynamics. Dissociative chemisorption probabilities as functions of impact parameters, collision energies, and a rovibrational state of a molecule are calculated. And the corresponding reactive cross sections are evaluated. Resonance formation in the low collision energy region is discussed.