Theoretical Kinetic Studies
About
The research group on theoretical kinetics investigates a wide range of chemical reactions of importance in the atmosphere, predicting reaction rates and product distributions using quantum chemical and theoretical kinetic methodologies. The use of theoretical methods allows the investigation of elementary reactions that are difficult to study experimentally, making this approach highly complementary to experimental work, and the theory-based results can be readily incorporated in atmospheric models.
Research Topics
- Chemistry of Criegee intermediates
- Atmospheric degradation of aromatic compounds
- Decomposition and isomerisation of alkoxy radicals
- Isomerisation of alkylperoxy radicals in OH regeneration and HOM formation
- Atmospheric oxidation of monoterpenes
- Structure-Activity relationships for reactive intermediates
- Theory-based support of experimental research
Our group is mostly involved in studies on reactive intermediates such as radicals and carbonyl oxides (alkoxy radicals, alkylperoxy radicals, Criegee intermediates). These species have access to a very diverse set of chemical reactions, allowing these species to break apart, re-arrange to a different species, or react with other molecules present in the atmosphere to combine to larger molecules, or create new molecular fragments. The competition between all these processes determines the atmospheric fate of any given compound, i.e. whether it will fall apart to small gaseous molecules, or instead form larger molecules that form particles, affect air quality and health, or have an influence on our climate.
Three approaches are used by our group. The first is to examine important reactions in high detail, to determine how the reaction works, how fast it goes as a function of the reaction conditions (.e.g temperature and pressure), and which products come out of it. This information is highly valuable to understand how the chemistry in the atmosphere proceeds. Secondly, we examine large chemical kinetic models of key organic material emitted to the atmosphere, and determine how it degrades step by step, in a complex network of hundreds of reactions, interacting with other species in the atmosphere. Finally, we examine systematic variations of molecules, all undergoing the same type of reaction. From these studies, we can derive so-called “structure-activity relationships” (SARs) which can predict the chemical activity of a new molecule, based solely on its structure. This information is needed for modeling studies, which attempt to explicitly describe the chemistry of many thousands of molecules in the atmosphere.
JUKINET Computational Cluster
The theoretical kinetics group runs a modest computational cluster, designed specifically for the type of calculations needed for our research. Some characteristics:
- Intel Xeon-based CPUs with up to 40 cores per node (dual cpu); 632 cores total
- Up to 1 TB of memory per node; 14 TB total
- Up to 8 TB of high-speed DAS disk scratch space per node; 120 TB total disk RAID
- Torque resource manager + Maui queuing system
- Quantum chemical and theoretical kinetic applications installed
The cluster is physically hosted at the JSC (Jülich Supercomputing Center).
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