The introduction of general numerical methods in the form of widely available software can have a dramatic effect on the development of a scientific field. In electronic structure theory, for example, general-purpose programs (such as GAUSSIAN, MOLCAS, MOLPRO...) combined with better computational resources have in part led to molecular electronic structure calculations becoming a ubiquitous tool in chemical research. Similarly, quantum dynamics methods based on the variational principle such as the Multi-Configuration Time-Dependent Hartree (MCTDH), hold out similar promise in the study of adiabatic and non-adiabatic processes, because of their generality, applicability and fast convergence towards the “exact” solution.Hence, the goal of the present proposal is to develop and apply for the first time the Multi-Layer (ML) variant of the MCTDH method to coherent control in large polyatomic molecules (i.e. more than 10 atoms). We plan to use benzopyran as a benchmark system in order to show that our strategy can be generally applied in the context of laser-driven control of photochemical reactivity involving large amplitude motions and multiple electronic potential energy surfaces. Which is the effect of the size of the system on the quantum-mechanical effects or how to generate general strategies to control the chemistry around a non-adiabatic event in complex molecules, are some of the open questions we aim to address in direct collaboration with experimentalists in the field. In the long-term, this development is expected to have a major impact, allowing fully accurate non-adiabatic dynamics simulations to be made not only in small molecular systems, but also routinely in large molecules with the ultimate goal of treating systems embedded in a complex environment such as a protein, a solvent or a matrix.