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dc.contributor.authorWang, Jueen_US
dc.contributor.otherDepartment of Physicsen_US
dc.date.accessioned2012-05-17T12:23:06Z
dc.date.available2012-05-17T12:23:06Z
dc.date.issued1-May-11en_US
dc.date.submittedMay-11en_US
dc.identifierWang_grad.sunysb_0771E_10479.pdfen_US
dc.identifier.urihttp://hdl.handle.net/1951/56149
dc.description.abstractAb initio molecular dynamics (AIMD) simulations of liquid water, based on density functional theory (DFT), yield structural and diffusive properties in reasonable agreement with experiment when artificially high temperatures are used in the simulations for gradient-corrected (GGA) functionals, with NVT ensemble. A series of simulations with GGA functionals is performed and underestimation of equilibrium density, at ambient conditions, is found. Electronic density of water molecules with several GGA functionals is examined and used to explain structural and dynamical property differences. Dispersive non-local electron-electron correlations are studied with a van der Waals density functional (vdW-DF) of Dion et al. When a vdW-DF is used, the density improves drastically and the experimental diffusivity is reproduced without the need of thermal corrections. The origin of the density differences between all the functionals is analyzed. It has been shown the vdW-DF increases the population of non-H-bonded interstitial sites, at distances between the first and second coordination shells. However, it excessively weakens the H-bond network, collapsing the second coordination shell. GaN/ZnO alloy semiconductors have been shown to be promising materials to serve as photo-anode in photocatalytical fuel cells. A thorough AIMD study of the non polar GaN(1010) surface with aqueous interface is carried out. It has been shown that water dissociation happens very fast within 1ps. Interacting OH dimers are found to account for around 80% of the dissociated water molecules through a hydrogen bond. A detailed study of the OH dimers shows their distinguishable structural, dynamical and electronic properties. Solvent water molecules interacting with a dissociating wet surface is also studied in detail, especially the hydrogen bond network. Proton diffusion is found starting from non-dissociated surface water molecules. The effective free energy barrier of proton diffusion is shown to be near room temperature thermal energy.en_US
dc.description.sponsorshipStony Brook University Libraries. SBU Graduate School in Department of Physics. Lawrence Martin (Dean of Graduate School).en_US
dc.formatElectronic Resourceen_US
dc.language.isoen_USen_US
dc.publisherThe Graduate School, Stony Brook University: Stony Brook, NY.en_US
dc.subject.lcshPhysicsen_US
dc.titleFirst Principle Study of Water: From Fundamental Properties to Photocatalytic Reactionen_US
dc.typeDissertationen_US
dc.description.advisorAdvisor(s): Maria Victoria Fernandez-Serra. Committee Member(s): Philip B. Allen; Thomas C. Weinacht; Michael G. White.en_US
dc.mimetypeApplication/PDFen_US


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