Citric acid is not only a molecule of fundamental importance for cell respiration but also used in multiple and varied industrial applications including food industry and pharma. The compound shows a high solubility in water and an can easily be supersaturated. In addition, citric acid crystallises in two different crystal forms from the same water solutions: the anhydrous crystal form results from slow cooling whilst rapid cooling leads to the monohydrate. This points towards aggregation in solution that is carried over to the hydrate, i.e. the interactions are 'frozen out' during crystallisation. It is the aim of this proposal to collect data on the solution state and investigate these by means of reverse Monte-Carlo simulations. Particular interest is in the solvation shells of the molecules, which will be compared to the neutron crystal structures and derived interaction energies.
