HR: 1340h
AN: B53C-1012    [Abstracts]
TI: Structure, Properties, and Reactions of Biogenic Manganese Oxides Predicted by Density Functional Theory.
AU: * O'Connor, M V
EM: moconnor@nature.berkeley.edu
AF: Department of Environmental Science, Policy and Management University of California, Berkeley, Hilgard Hall MC 3110, Berkeley, CA 94720 United States
AU: Sposito, G
EM: gsposito@nature.berkeley.edu
AF: Department of Environmental Science, Policy and Management University of California, Berkeley, Hilgard Hall MC 3110, Berkeley, CA 94720 United States
AU: Refson, K
EM: krefson@rl.ac.uk
AF: Rutherford Appleton Lboratory, Chilton Oxfordshire, Didcot, OX12 0QX United Kingdom
AB: Biogenic manganese oxides are nanoparticles produced by a wide variety of microorganisms. They typically exhibit short-range order and have the characteristic 7.2 Angstrom layer spacing of the birnessite family of manganese oxides. Density functional theory(DFT) has been used to study the properties of the oxide structures. The effects of different spin states have been modeled; preliminary results show that different spin states have a large effect on the physical structure of the crystals. Biogenic manganese oxides contain Mn(IV) vacancy sites, leading to a negative structural charge. The reaction of cations and water with these vacancies also have been probed using DFT modeling.
DE: 0330 Geochemical cycles
SC: Biogeosciences [B]
MN: 2004 AGU Fall Meeting