Excited-state transition metal (TM) complexes have received great attention both for their functional capabilities (solar energy conversion, molecular data storage, etc.) and their properties optimal for time-resolved experimental investigations. As in most cases the dynamics are probed in solution phase, the already complex excited-state processes, such as electronic transitions and nuclear relaxation, are further complicated by solvation. Time-resolved Xray scattering is a powerful technique to follow excited-state structural variations, also in solution, but the data analysis heavily relies on the simulation of solvation structure; theory thus has an essential role in extracting the structural information from the complex experimental data.