PDF Studies of hexagonal and cubic ices

We have successfully applied Hirshfeld Atom Refinement to X-ray diffraction data to determine the average structures of Ice VI [IUCrJ (2022) 9, 573-579] and IceVII (yet unpublished) and hexagonal ice (Ih - HAR refinement of electron diffraction data, in press now). In our previous experiment we obtained excellent data from Pearl which are already refined for ice VII and now being refined for ice VI.By performing neutron PDF studies of hexagonal and cubic ice, we want to establish the local structures of these ices, and compare them with the average structure from HAR. Additionally, we want to use these PDF neutron results for the sake of comparison with X-ray PDF results obtained for the same forms of ice at the same pressure and temperature when spherical and aspherical atomic scattering factors are used. We ahave submitted 3 different project to ESRF to get X-ray PDF data which will complement results of this experiment. We hope that state of the art PDF data will be an excellent reference points and help to develope a new HAR like PDF approach and possibly confirm disorder of both H and O-atoms (which we sometimes observe in our HAR refinements)