UC San Diego

Structures and Dynamics of bulk, surface and the mineral/ aqueous fluid interface regions for geochemically important metal oxide/oxihydroxides including goethite, hematite and corundum have been investigated by performing Ab Initio study. In this dissertation, plane-wave based static optimization is used to calculate structural and electronic structural properties of mineral bulk and surface systems. Ab-initio Molecular Dynamics (AIMD) is employed to probe the dynamics properties of mineral/ aqueous fluid interfaces. In the first part, the experimental and computational progress has been introduced in chapter 1. The theoretical backgrounds and applications including first principle methods as well as AIMD are briefly summarized in chapter 2. In the second part, the properties of mineral bulk materials are calculated and analyzed in chapter 3. The comparison of experimental and computational in structural results provides an overall understanding of the accuracies of various applications and methods in first principle framework. The analysis of electronic structure gives insight about different first principle methods in simulation. In the third part, simulations of different surface and aqueous fluid interfaces of minerals (goethite (100) in chapter 4, hematite (001) and (012) in chapter 5, corundum (001) in chapter 6) are carried out. The interaction of ordered water layers with those mineral surfaces is of great interest for both fundamental science and applications. Different studies including water adsorption process on surface, interfacial hydrogen bond analysis, types of water molecules analysis, projected density of states for interfacial atoms, electron density profiles and etc have been used to investigate the ordered water layers on surfaces