This computational project addresses general, crucial questions regarding charge-transfer processes in natural photosynthesis to identify the key features in the design of a bio-mimetic rectifier. In particular, we want to elucidate the detailed path of primary electron transfer in the reaction center of a prototypical photosynthetic system, and understand how nature prevents charge recombination to achieve an efficient unidirectional electron transport. We will explore the likely scenario of a proton-coupled electron transfer process being active in the primary step, and understand its role in stabilizing the electron path through the complex hydrogen-bond network of the reaction center. We will then proceed with a systematic build-up of simpler acceptor-donor models for artificial photosynthesis, where we do not only mimic the natural system but also optimize various specific aspects of the electron-transfer process. Our goal is to identify realistic building blocks in the core of an artificial system so that the transfer mechanism is characterized by low recombination rates as well as reduced energy losses along the charge-transfer chain. To properly account for the microscopic nature of the problem, we need to go beyond effective Hamiltonian models and include a detailed electronic/atomistic description of the system. The success of this project requires a range of computational methods able to span different level of accuracy, and length and time scales. Here, we face these challenges by using state-of-the-art electronic structure calculations and ab-initio molecular dynamics simulations.