Liquid water structure from X-ray absorption and emission, NMR shielding and X-ray diffraction

Here we investigate to what extent X-ray absorption (XAS) and emission (XES) spectroscopy, the oxygen-oxygen radial distribution function and σ(1H) and σ(17O) NMR shielding can be represented by a common set of model structures of liquid water. This is done by using a Monte Carlo-based fitting technique which fits the spectra based on a library of ∼1400 precomputed spectra and assigns weights to contributions from different model structures. These are then used to reweight the contributions from the structures in the library to reveal classes of structures that are over- or under-represented in the library. The goal is to include different experimental data sets which are sensitive to different aspects of liquid water structure and thus narrow down which types of structures must exist in the real liquid.