Short range ordering in H2O and D2O ices; XI, Ic, Ih, and liquid water by Pair Distribution Function with aspherical atomic scattering facto

Ice is water frozen into a solid state. There are at least 20 different polymorphic forms of ice. The aims of this proposal are multi-fold: (a) to collect excellent quality X-ray PDF data at ambient pressure for different phases of H2O and D2O ices and liquid water (from 300K down to 10K); (b) to refine PDFs using Independent Atom Model (IAM) with Reversed Monte Carlo (RMC) modelling of all these structures, (c) use the same X-ray PDF data utilising Hirshfeld Atom Refinement which is based on aspherical atomic scattering factors, and to compare the results obtained using these two approaches, (d) to compare results of our experiments and refinements to the neutron PDFs. We propose 6 shifts for studies of both H2O and D2O ices to get in total ca. 30-40 PDF data sets for both categories of ices. Validation of Quantum Crystallographic PDF approach will open new research opportunities not only in an incredibly intense ice research but also in all other fields which apply PDFs .