Non-adiabatic properties of nuclear motion

Project ID: 2228cd1410 (You will need this ID for your application)

UCL Lead department: Physics and Astronomy

Project Summary:

The Born-Oppenheimer approximation which separates the electronic and nuclear motions in molecules is the bedrock of chemical physics. However in growing number of important cases, such as ones encountered in photophysics and photochemistry, this approximation is not adequate. A well-documented example is the Berry phase which arises as a consequence of making the separate treatment of electronic and nuclear motion in the region where two potential energy surfaces cross. The aim of the project is to develop a full non-adiabatic, symmetry adapted, rotation-vibrational electronic computational method from first principles for polyatomic systems characterized by conical intersections. The method will retain the many advantages of the current Born-Oppenheimer procedures already developed by the research group and use these to provide a starting point to model beyond the Born-Oppenheimer effects introduced by inclusion of non-adiabatic couplings. We plan to study the Berry phase and non-adiabatic dynamics in the excited electronic states of water, a molecule, crucial for accurate modelling and controlling the UV absorption in the atmosphere of the Earth and other planets, C3, a key molecule in combustion and Ammonia, which is the biggest man-made atmospheric pollutant.