TY - JOUR A1 - Sellberg, Jonas A. A1 - McQueen, Trevor A. A1 - Laksmono, Hartawan A1 - Schreck, Simon A1 - Beye, Martin A1 - DePonte, Daniel P. A1 - Kennedy, Brian A1 - Nordlund, Dennis A1 - Sierra, Raymond G. A1 - Schlesinger, Daniel A1 - Tokushima, Takashi A1 - Zhovtobriukh, Iurii A1 - Eckert, Sebastian A1 - Segtnan, Vegard H. A1 - Ogasawara, Hirohito A1 - Kubicek, Katharina A1 - Techert, Simone A1 - Bergmann, Uwe A1 - Dakovski, Georgi L. A1 - Schlotter, William F. A1 - Harada, Yoshihisa A1 - Bogan, Michael J. A1 - Wernet, Philippe A1 - Föhlisch, Alexander A1 - Pettersson, Lars G. M. A1 - Nilsson, Anders T1 - X-ray emission spectroscopy of bulk liquid water in "no-man's land" JF - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistr N2 - The structure of bulk liquid water was recently probed by x-ray scattering below the temperature limit of homogeneous nucleation (T-H) of similar to 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 T-H 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 1b(1)' and 1b(1)" 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. (C) 2015 AIP Publishing LLC. Y1 - 2015 U6 - https://doi.org/10.1063/1.4905603 SN - 0021-9606 SN - 1089-7690 VL - 142 IS - 4 PB - American Institute of Physics CY - Melville ER -