Computationally Intensive Research Project
Reliable Relativistic Quantum Chemistry Calculations for Molecules with Heavy Elements
MSC News
Additional Information
Wibe A. de Jong1, Lucas NMN Visscher2, Bruce E. Bursten3, Jochen Autschbach4, David A. Dixon5, Hiyong Zhang6, Benjamin P. Hay7, Jun Li1, Michael Leland McKee8, Chang-Guo NMN Zhan9, Angela K Wilson10, Stan Jack Anton Van Gisbergen2, Kenneth G. Dyall11
1Environmental Molecular Sciences Laboratory, 2Vrije Universiteit Amsterdam, 3Ohio State University, 4State University of New York at Buffalo, 5University of Alabama, 6Lawrence Berkeley National Laboratory, 7Pacific Northwest National Laboratory, 8Auburn Unversity, 9University of Kentucky, 10University of North Texas, 11Schrondinger Inc.
FY07 Allocation - 800,000
Abstract
We propose to perform ab initio electronic structure calculations based on wavefunction theory and density functional theory (DFT). The calculations will include a proper treatment of relativistic effects to investigate heavy element systems. Our computational studies will provide us with new understanding about the role of these effects in a broad range of chemical systems containing actinides, lanthanides, and heavy transition metals; these chemical systems are critical to Department of Energy (DOE) missions including energy, environmental restoration, and Homeland Security. The specific molecular species to be studied will be selected to complement other experimental and theoretical efforts at PNNL, other national laboratories, industry, and universities, with emphasis on DOE's environmental cleanup mission and on obtaining new scientific information about these novel molecular systems. This proposal is a renewal of our current, highly successful, EMSL Grand Challenge project that will be ending this year. A wide variety of relativistic and non-relativistic quantum chemical methods will be employed to explore actinide; lanthanide; heavy transition metal; and heavy, main-group element chemistry. Our goal is make use of state-of-the-art computational chemistry methods to give a firm theoretical basis to this area, to provide interpretations of complex experimental data, and to extend expensive experimental results into new areas of parameter space. Information that can be obtained for heavy, element-containing molecules includes, but is not limited to:
- molecular structure and complex formation
- spectroscopic properties including electronic (e.g., UV-vis), vibrational (e.g., IR and Raman), and nuclear magnetic resonance
- complexation binding energies
- redox chemistry
- the role of solvation and other environmental effects.
Our studies will contribute to characterizing the interaction of the actinide, lanthanide, and heavy transition metal ions with organic complexing agents that are present in nuclear processing waste tanks and with anions such as carbonates and silicates that are present in natural aqueous systems. The results will lead to a better understanding of their fate and transport in the environment and interactions with new materials, such as phosphates and amides, for the design of innovative in situ remediation technologies and separation systems. The results of structural, spectroscopic, and energetics calculations will aid experimental researchers in their efforts to interpret complex experimental results and to provide a firm conceptual foundation for our understanding of these molecules. The proposed work will allow scientists to tackle the nature of excited states, a field that has been obscured because of the difficulty of including multi-reference character and spin-orbit coupling effects, in heavy element compounds. The theoretical and computational results obtained from our calculations will be an invaluable supplement to current, very expensive experimental studies of the actinides, lanthanides, and heavy transition metal elements, allowing limited experimental data to be extrapolated to many other research areas of interest.
