HR: 12:05h
AN: V21E-08 INVITED     [PDF]
TI: Mineral Surfaces From First principles: Structure, Adsorption and Hydration
AU: * Artacho, E
EM: emilio@esc.cam.ac.uk
AF: Department of Earth Sciences University of Cambridge, Downing Street, Cambridge, CB2 3EQ United Kingdom
AU: Fernandez-Serra, M V
EM: mfer01@esc.cam.ac.uk
AF: Department of Earth Sciences University of Cambridge, Downing Street, Cambridge, CB2 3EQ United Kingdom
AU: Archer, T D
EM: tom00@esc.cam.ac.uk
AF: Department of Earth Sciences University of Cambridge, Downing Street, Cambridge, CB2 3EQ United Kingdom
AU: Wakelin, J
EM: jwak02@esc.cam.ac.uk
AF: Department of Earth Sciences University of Cambridge, Downing Street, Cambridge, CB2 3EQ United Kingdom
AU: Dove, M T
EM: martin@esc.cam.ac.uk
AF: Department of Earth Sciences University of Cambridge, Downing Street, Cambridge, CB2 3EQ United Kingdom
AB: Atomic scale phenomena occurring at the interface of minerals and water are, on one hand, very important in Earth and Environmental Sciences, and, on the other, extremely difficult to address, either from experiments or from simulations. The altered chemical bonds at surfaces demand quantum-mechanical first-principles simulation tools, while the complexity of the mineral surfaces and of water itself demand large simulation cell sizes and long simulation times, respectively. We approach the problem from two opposite starting points: (i) from the dry side: studying the effect of the first water layers on mineral surfaces, and (ii) from the wet side: studying liquid water and its response to the presence of ions and surfaces. This double route is justified by the very different characteristic time scales in the wet surface problem: some water molecules bind to the surface for very long times as compared to typical simulation times (picoseconds), while other molecules diffuse quite freely in the liquid. After a brief description of the methodology we use, based on linear-scaling density-functional theory, results will be presented for (i) the adsorption of pollutants onto dry clay surfaces and how the adsorption characteristics are modified by water molecules;(ii) the adsorption of water on calcite surfaces; and (iii) the characteristics of liquid water as described by our method.
DE: 3947 Surfaces and interfaces
DE: 3994 Instruments and techniques
SC: Volcanology, Geochemistry, Petrology [V]
MN: 2003 Fall Meeting