We report measurements of the non-resonant inelastic x-ray scattering (NRIXS) from the O 1s orbitals in ice Ih, and also report calculations of the corresponding spectra for ice Ih and several other phases of water ice. We find that the intermediate-energy fine structure may be calculated well using an ab initio real-space full multiple scattering approach, and that it provides a strong fingerprint of the intermediate-range order for some ice phases. These results have important consequences for future NRIXS measurements of high-pressure phases of ice and also may call into question the assumption that the wavefunctions for final states within a few eV of the absorption edge are strongly localized.
@article{arxiv.0801.1853,
title = {Intermediate-Range Order in Water Ices},
author = {T. T. Fister and K. P. Nagle and F. D. Vila and G. T. Seidler and C. Hamner and J. O. Cross and J. J. Rehr},
journal= {arXiv preprint arXiv:0801.1853},
year = {2008}
}