title: X-ray emission spectroscopy of bulk liquid water in "no-man's land".
abstract: The structure of bulk liquid water was recently probed by x-ray scattering below the temperature limit of homogeneous nucleation (TH) of ∼232 K [J. A. Sellberg et al., Nature 510, 381-384 (2014)]. Here, we utilize a similar approach to study the structure of bulk liquid water below TH using oxygen K-edge x-ray emission spectroscopy (XES). Based on previous XES experiments [T. Tokushima et al., Chem. Phys. Lett. 460, 387-400 (2008)] at higher temperatures, we expected the ratio of the 1b1' and 1b1″ peaks associated with the lone-pair orbital in water to change strongly upon deep supercooling as the coordination of the hydrogen (H-) bonds becomes tetrahedral. In contrast, we observed only minor changes in the lone-pair spectral region, challenging an interpretation in terms of two interconverting species. A number of alternative hypotheses to explain the results are put forward and discussed. Although the spectra can be explained by various contributions from these hypotheses, we here emphasize the interpretation that the line shape of each component changes dramatically when approaching lower temperatures, where, in particular, the peak assigned to the proposed disordered component would become more symmetrical as vibrational interference becomes more important.
authors: SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory,2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors: Jonas A
authors: JA
authors: Sellberg
authors: SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory,2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors: Trevor A
authors: TA
authors: McQueen
authors: PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors: Hartawan
authors: H
authors: Laksmono
authors: Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors: Simon
authors: S
authors: Schreck
authors: Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors: Martin
authors: M
authors: Beye
authors: Center for Free-Electron Laser Science, DESY, Notkestraße 85, 22607 Hamburg, Germany.
authors: Daniel P
authors: DP
authors: DePonte
authors: MAX-lab, P.O. Box 118, 221 00 Lund, Sweden.
authors: Brian
authors: B
authors: Kennedy
authors: Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, P.O. Box 20450, Stanford, California 94309, USA.
authors: Dennis
authors: D
authors: Nordlund
authors: PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors: Raymond G
authors: RG
authors: Sierra
authors: Department of Physics, AlbaNova University Center, Stockholm University, S-106 91 Stockholm, Sweden.
authors: Daniel
authors: D
authors: Schlesinger
authors: RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Hyogo 679-5148, Japan.
authors: Takashi
authors: T
authors: Tokushima
authors: Department of Physics, AlbaNova University Center, Stockholm University, S-106 91 Stockholm, Sweden.
authors: Iurii
authors: I
authors: Zhovtobriukh
authors: Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors: Sebastian
authors: S
authors: Eckert
authors: SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory,2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors: Vegard H
authors: VH
authors: Segtnan
authors: Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, P.O. Box 20450, Stanford, California 94309, USA.
authors: Hirohito
authors: H
authors: Ogasawara
authors: Photon Science, DESY, Notkestraße 85, 22607 Hamburg, Germany.
authors: Katharina
authors: K
authors: Kubicek
authors: IFG Structural Dynamics of (Bio)chemical Systems, Max Planck Institute for Biophysical Chemistry, Am Faßberg 11, 37070 Göttingen, Germany.
authors: Simone
authors: S
authors: Techert
authors: Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors: Uwe
authors: U
authors: Bergmann
authors: Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors: Georgi L
authors: GL
authors: Dakovski
authors: Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors: William F
authors: WF
authors: Schlotter
authors: Institute for Solid State Physics (ISSP), University of Tokyo, Kashiwanoha, Kashiwa, Chiba 277-8581, Japan.
authors: Yoshihisa
authors: Y
authors: Harada
authors: PULSE Institute, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors: Michael J
authors: MJ
authors: Bogan
authors: Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors: Philippe
authors: P
authors: Wernet
authors: Institute for Methods and Instrumentation for Synchrotron Radiation Research, Helmholtz-Zentrum Berlin für Materialien und Energie GmbH, Albert-Einstein-Straße 15, 12489 Berlin, Germany.
authors: Alexander
authors: A
authors: Föhlisch
authors: Department of Physics, AlbaNova University Center, Stockholm University, S-106 91 Stockholm, Sweden.
authors: Lars G M
authors: LG
authors: Pettersson
authors: SUNCAT Center for Interface Science and Catalysis, SLAC National Accelerator Laboratory,2575 Sand Hill Road, Menlo Park, California 94025, USA.
authors: Anders
authors: A
authors: Nilsson