Molecular modeling of core ionization spectra of adsorbed molecules on ice
Ice is ubiquitous in the environment in the form of snow, sea ice, or cirrus clouds and can play an important role as a catalyst for reactions between atmospheric trace gases or as a trace-gas scavenger. Uptake of oxygenated and halogenated molecules to ice and snow has been proposed to be a major loss process from the atmosphere with impacts on the atmospheric oxidation capacity. X-ray photoelectron spectroscopy (XPS) is among the most sensitive probe of surface elemental composition that is also chemically specific.
The goal of the internship provide a valuable theoretical support for XPS experimental results [1,2] by means of a so called “multi-scale” approach, allowing the treatment of large systems. Classical molecular dynamics (MD) will be first employed to determine the stable adsorption sites at the air/ice interface as performed in earlier studies .
These MD calculations will be followed by electronic structure calculations combining the equation-of-motion coupled cluster (EOM-IP-CCSD) and frozen density embedding (FDE) methods , in order to calculate the effects of the ice interface on the XPS spectra of target halogenated molecules including statistical (configurational) effects.
At the end of the internship, the student will have acquired some new skills in numerical simulations in molecular physics and quantum chemistry, coding experience (python scripting) and will have learned more about photoelectron spectroscopies.
Keywords: Ice, simulations, calculations, photoionization spectrum
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