Solving the TDSE for chemically relevant systems is challenging because the computational effort scales exponentially with the number of nuclear coordinates (curse of dimensionality). In practice, this requires careful selection of few, typically 2-3, internal coordinates, which contribute most to the chemical or physical process of interest (e.g. elongation of chemical bonds). To achieve this goal, we develop workflows and tools to perform grid-based wave packet dynamics in reactive coordinates.

Further increasing the complexity, molecular processes usually take place in solvents or other environments, which can influence the dynamics through steric and electronic interactions. We therefore develop multiscale methods to couple this environmental influence to the dynamics of the target system.

Fully modelling the effects of a laser pulse at sub-femtosecond resolution requires propagating not only a nuclear wave packet on a potential energy surface but also including the motion of the electrons. To achieve this goal, we develop and apply the NEMol ansatz, enabling us to study the temporal evolution of electron density coupled to the nuclear quantum dynamics. This allows us to simulate the control of both electronic and nuclear motion with the help of tailored laser fields.