Department of Earth Sciences
Researcher:
Lemke Kono Heinz, Assistant Professor (kono@hkucc.hku.hk)
Project Title:
Thermodynamic stability of hydrogen bonded clusters in geological environments
Project Description:
These calculations center around the multi-step CBS-QCI/APNO and G3 level methods. The first step in this project is to obtain reliable interaction energies, enthalpies of reaction and Gibbs free energies for a suite of experimentally well-document systems, e.g. gas phase multimers (alcohols, nitriles etc.) for which gas phase association enthalpies and entropies are reported.
Project Duration:
12 months
Project Significance:
To date, no systematic studies have been conducted to test the reliability of Gn and CBS-x procedures for the calculation of association equilibria of hydrogen bonded clusters in nature. These studies are intended to test the reliability of the above methods and expand their application to systems for which there are no experimental logK data available.
Results Achieved:
- Lemke K.H. and Seward T.M. Solvation processes In steam: ab initio calculations of ionsolvent structures and clustering equilibria, Geochimica et Cosmochimica Acta, 2008, 14, 3293-3310.
- Lemke K.H. and Seward T.M. Ab initio investigation of the structure, stability and atmospheric distribution of molecular clusters containing H2O, CO2 and N2O, Journal of Geophysical Research - Atmospheres, 2008, 113, D19304.
- Stefasson A., Lemke K.H. and Seward T.M. Iron(III) complexation in hydrothermal solutions: An experimental and theoretical study, Proceedings of the 15th International Conference on the Properties of Water and Steam, 2008, 1-7.
- Sadjadi S.A., Butt S.K. and Lemke K.H. Thermodynamic and structural stability of (CO2)(n) n=2-4: An ab initio and QTAIM Study, Geochimica et Cosmochimica Acta, 2009, A1140.
- Lemke K.H., Butt S.K. and Seward T.M. The Structure and stability of metal Water clusters in high temperature low density fluids, Geochimica et Cosmochimica Acta, 2009, A743.
- Seward T.M., Lemke K.H., Sadjadi, S.A., Henderson C.M.B. and Charnock J.M. (2010): An X-ray absorption spectroscopic and ab initio computational study of the Cd(II) aquated ion and chloridocadmium(II) complexing in hydrothermal solutions. In prep. for: Geochimica et Cosmochimica Acta.
- Sadjadi, S.A. Lemke, K.H. (2010) Ab initio calculations of the thermal stability of carbon dioxide dimers and trimers. In prep. for: Journal of the American Chemical Society.
