Many-body potential models for molecules and ions in atmospheric aerosol droplets

Time period: 2012-01-01 to 2015-12-31

Project leader: Daniel Spångberg

Funder: Swedish Research Council

Type of award: Project grant

Total fundning: 2 034 994 SEK

I plan to develop new accurate many-body potential models for the description of molecular interactions in the bulk and at liquid surfaces, primarily for the study of the molecular level distribution of molecules and ions in atmospheric aerosol droplets.Computer simulation can give very detailed molecular level information, but in order to quantitatively determine the distribution of molecules, for instance close to a liquid surface, very accurate molecular models are required. Current empirical models in the literature give contradictory results for this distributions, why new more accurate models are required. So-called ab initio molecular dynamics methods are far too expensive to allow the treatment of systems larger than about a hundred molecules or allow simulation lengths of the timescales required for the study of the distribution of molecules close to surfaces.The potential models will be developed by using very high-level ab initio calculations for large molecular clusters in the gas phase. They will be sufficiently flexible to handle the change in molecular properties from the gas phase to the liquid phase. When used in molecular dynamics simulations, they will also be many magnitudes faster than ab initio molecular dynamics methods.While the models can be used generally for many problems, in this project I plan to focus on the molecular level distribution of molecules and ions relevant for atmospheric chemistry.