Our research focuses on the interaction between state-of-the-art laser fields with atoms and small molecules. We develop world-leading HPC computer codes, based on R-matrix theory, to solve the time-dependent Schrodinger equation from first principles. We describe real systems, with full inclusion of the interplay between electrons. The codes have been applied to a wide range of physical processes, including, amongst others, harmonic generation, and transient absorption spectroscopy.