Objective Earth’s atmosphere is a massive photochemical reactor, and human activities are changing its chemical composition, impacting both climate and air quality. Detailed chemical mechanisms – constructed from coupled kinetic networks of thousands of elementary reactions – are crucial in advancing our fundamental understanding of atmospheric chemistry, and developing reliable predictive models. Because the elementary mechanistic details of volatile organic compound (VOC) oxidation are often beyond the reach of experiment, in silico molecular kinetics studies (utilizing ab initio quantum chemistry and nonequilibrium statistical mechanics) are increasingly used to construct atmospheric chemistry models – particularly for describing VOC kinetics on electronic ground states.For electronic excited states, in silico studies of VOC kinetics remain an almost entirely unexplored horizon, even though light absorption and dynamics on excited states initiate most of the atmosphere’s chemistry. Neglect of excited states is increasingly problematic: for example, standard ground-state oxidation kinetics cannot explain experimental results for isoprene and toluene, two of the troposphere’s most abundant VOCs. By fusing state-of-the-art ab initio quantum chemistry, excited-state dynamics, and nonequilibrium statistical mechanics, we will carry out detailed investigations of atmospheric VOC intermediates, developing new software tools, methods, and results for direct comparison with experiments. These tools will enable theoretical chemists and atmospheric modelers to calculate in silico absorption cross-sections, quantum yields, and photolysis rate coefficients for electronic excited states of key VOCs, providing insight into how excited-state dynamics impact atmospheric chemistry on global and regional scales. This project will blaze a trail in an exciting new area of physical chemistry, tightening the link between fundamental in silico chemical dynamics and applied atmospheric chemistry. Fields of science natural scienceschemical scienceselectrochemistryelectrolysisnatural scienceschemical sciencesphysical chemistryphotochemistrynatural scienceschemical sciencesphysical chemistryquantum chemistrynatural sciencesphysical sciencesopticsspectroscopyabsorption spectroscopynatural sciencesphysical sciencesclassical mechanicsstatistical mechanics Keywords Excited-state dynamics Atmospheric Chemistry Nonadiabatic effects Kinetic models Oxidation chemistry Programme(s) H2020-EU.1.3. - EXCELLENT SCIENCE - Marie Skłodowska-Curie Actions Main Programme H2020-EU.1.3.2. - Nurturing excellence by means of cross-border and cross-sector mobility Topic(s) MSCA-IF-2015-EF - Marie Skłodowska-Curie Individual Fellowships (IF-EF) Call for proposal H2020-MSCA-IF-2015 See other projects for this call Funding Scheme MSCA-IF - Marie Skłodowska-Curie Individual Fellowships (IF) Coordinator UNIVERSITY OF BRISTOL Net EU contribution € 183 454,80 Address BEACON HOUSE QUEENS ROAD BS8 1QU Bristol United Kingdom See on map Region South West (England) Gloucestershire, Wiltshire and Bristol/Bath area Bristol, City of Activity type Higher or Secondary Education Establishments Links Contact the organisation Opens in new window Website Opens in new window Participation in EU R&I programmes Opens in new window HORIZON collaboration network Opens in new window Total cost € 183 454,80