This project works on computational modelling of photochemical processes initiated by visible and UV light, relevant in biology and technological processes and also in the modelling of charge transfer along DNA chains, of potential interest for the nanosciences.This sub-area includes considerable interest in the application of research aimed at the development of new concepts and methods for the study of photochemical processes of interest.Our main subjects of research are: • Photochemistry and photophysics of the nitrogenousDNA bases.Here we focus on modelling DNA interactions with UV light.Our research focuses on nitrogenous bases, which are the main components of DNA that absorb UV radiation.Using our calculations we propose to interpret high-resolution laser spectroscopy experiments applied to model systems and DNA to study the effect of UV radiation on natural DNA.Mechanisms have therefore been determined that enable a benign dissipation of UV-excitation energy to avoid processes that could induce mutations.• Mechanistic basis of photoprotectors.Photoprotectors are molecules used in industry as additives for protecting the materials.They absorb radiation and dissipate it efficiently and benignly, protecting the material from light-induced degradation.The chemical reaction regulating this process is a excited-state hydrogen transfer, and we have studied the factors responsible for the effectiveness of the decay that prevents damage to DNA.• Electronic transfer in DNA stacksExperiments carried out on the DNA of research groups from Europe, USA and Japan have demonstrated that if an electronic load is injected DNA this can migrate along the central column made up of stacked nitrogenous bases.This has opened the way for possible uses DNA as a conductor or semiconductor in nanotechnology.Our goal in this field involves determining the parameters that govern charge transfers to provide the physical basis for future applications based on this process.• Methodological developments.Our main goal in this field is a mathematical analysis of the potential energy surfaces calculated.