  The past decade or so has witnessed a large number of articles about water
structure. The most incisive experiments involve radiation with a wavelength
compatible with the observed inter-molecular separations found in water, of
order $\sim 3$\AA, in other words mostly $<$1eV neutrons and $>$10keV x-rays.
Because x-rays are scattered by electrons while neutrons are scattered by
nuclei, the two probes give complementary information about the three site-site
radial distribution functions for water, namely O-O, O-H and H-H. Here a
version of Monte Carlo simulation called Empirical Potential Structure
Refinement is used to devise an empirical intermolecular potential which
attempts to drive the simulated radial distribution functions as close as
possible to the data. New x-ray and neutron scattering data on water in the
temperature range 280 - 365K are presented for the first time, alongside a new
analysis of some much older neutron data on ice 1h at 220K. This temperature
analysis, above and below the water freezing point of water, reveals some
non-intuitive water properties in the liquid and solid states.
