The paper is organized as follows: First, we identify the aforementioned central complexwater geometries. We use the dimers to benchmark a series of DFT and long-range dispersion treatments against a more accurate model for electronic correlation. We then include results from a molecular mechanics (MM) force field into the benchmark and increase the size of the test systems. Finally, we correlate the water-shell encompassing the complex to the MDsampled average solvation structure, and analyse the effects of finite-size simulation cells.