Generating interstitial water within the persisting tetrahedral H-bond network explains density increase upon compressing liquid water

• 成果类型: Article
• 署名作者: Forster, Mirko; Ukoji, Nnanna; Sahle, Christoph J.; Niskanen, Johannes; Sakrowski, Robin; Surmeier, Goran; Weis, Christopher; Irifune, Tetsuo; Imoto, Sho; Yavas, Hasan; Huotari, Simo; Marx, Dominik; Sternemann, Christian; Tse, John S.
• 署名单位: Dortmund University of Technology; University of Saskatchewan; European Synchrotron Radiation Facility (ESRF); University of Turku; Ehime University; Ruhr University Bochum; Helmholtz Association; Deutsches Elektronen-Synchrotron (DESY); Stanford University; United States Department of Energy (DOE); SLAC National Accelerator Laboratory; University of Helsinki
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-12552
• DOI: 10.1073/pnas.2403662121
• 发表日期: 2024-09-24
• 关键词: x-ray-scattering; functional theory; edge spectrum; ice-i; pressure; spectroscopy; osmolytes; hydration; DYNAMICS; transformations

摘要

Despite its ubiquitous nature, the atomic structure of water in its liquid state is still controversially debated. We use a combination of X-ray Raman scattering spectroscopy in conjunction with ab initio and path integral molecular dynamics simulations to study the local atomic and electronic structure of water under high pressure conditions. Systematically increasing fingerprints of non-hydrogen-bonded H2O molecules in the first hydration shell are identified in the experimental and computational oxygen K-edge excitation spectra. This provides evidence for a compaction mechanism in terms of a continuous collapse of the second hydration shell with increasing pressure via generation of interstitial water within locally tetrahedral hydrogen-bonding environments.