Future advanced gravitational wave detectors will need to be constructed using ultra low loss materials to achieve the desired sensitivity levels. Coating thermal noise which is related to mechanical loss has been determined to be a limiting factor for the sensitivity of these detectors and must be reduced. To achieve this goal, work is on going to identify the causes of coating mechanical loss. Recent experiments suggest this is micro-structural in origin, thus determining the structural features of coatings via appropriate modelling is of interest. It will be shown that through Transmission Electron Microscopy and reduced density function analysis, the local structural changes due to doping of coating materials can be identified. Furthermore by using this data as an empirical constraint for combined reverse Monte Carlo and Density Functional Theory simulations the trends seen in the data can be replicated in the modelling.