Fundamental Assessment of the Accuracy of Time-Dependent Density Functional Theory
EMSL Project ID
8193
Abstract
Time-dependent density functional theory (TD-DFT) has become an increasingly popular technique for addressing electronically excited states of molecules. As evidence of its success, TD-DFT has found application in nearly every area of chemistry, particularly in environmental studies of atmospheric contamination, pesticide photodegradation, and photovoltaic cells. The types of molecules in these studies range from small organic radicals to large compounds containing one or more metal atoms. Yet, despite this variety in the applications of TD-DFT, the fundamental benchmarking of the procedure has largely been limited to simple organic species. It is not clear how valid the conclusions from studies of these homogenous test molecules are when applied to the disparate systems of interest to environmental chemists. In addition, details on the most accurate parameters in TD-DFT, such as functional and basis set, have not been systematically investigated. Addressing these deficiencies will lead to greater accuracy in future studies on photochemically active species. This proposal outlines a broad, multidimensional benchmarking study investigating the fundamental accuracy of TD-DFT when applied to cations, anions, organic species, inorganic species, organometallic species, and species where relativistic effects play an important role. In addition, the effect of recent advances in asymptotically correct functionals and extremely large basis sets will be investigated. Finally, this benchmarking effort will also include the first exhaustive study of electronic transitions from open-shell species, such as radicals and certain metal-containing moieties. As a result of the conclusions of this systematic investigation, computational chemists will be equipped with a sense of the absolute accuracy possible with TD-DFT. They will also have confidence that this technique can be applied to any system, be it a small organic molecule or a large metallopolymer. Finally, a recipe for the most accurate parameters to use in a TD-DFT study will be delineated.
Project Details
Project type
Capability Research
Start Date
2004-04-01
End Date
2005-08-02
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Bailey VL, SJ Fansler, JC Stegen, and LA McCue. 2013. "Linking Microbial Community Structure to ?-Glucosidic Function in Soil Aggregates." The ISME Journal 7(10):2044-2053. doi:10.1038/ismej.2013.87