title: The temperature dependence of intermediate range oxygen-oxygen correlations in liquid water.
abstract: We analyze the recent temperature dependent oxygen-oxygen pair-distribution functions from experimental high-precision x-ray diffraction data of bulk water by Skinner et al. [J. Chem. Phys. 141, 214507 (2014)] with particular focus on the intermediate range where small, but significant, correlations are found out to 17 Å. The second peak in the pair-distribution function at 4.5 Å is connected to tetrahedral coordination and was shown by Skinner et al. to change behavior with temperature below the temperature of minimum isothermal compressibility. Here we show that this is associated also with a peak growing at 11 Å which strongly indicates a collective character of fluctuations leading to the enhanced compressibility at lower temperatures. We note that the peak at ∼13.2 Å exhibits a temperature dependence similar to that of the density with a maximum close to 277 K or 4 °C. We analyze simulations of the TIP4P/2005 water model in the same manner and find excellent agreement between simulations and experiment albeit with a temperature shift of ∼20 K.
authors: Department of Physics, AlbaNova University Center, Stockholm University, SE-106 91 Stockholm, Sweden.
authors: Daniel
authors: D
authors: Schlesinger
authors: Department of Physics, AlbaNova University Center, Stockholm University, SE-106 91 Stockholm, Sweden.
authors: K Thor
authors: KT
authors: Wikfeldt
authors: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors: Lawrie B
authors: LB
authors: Skinner
authors: X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors: Chris J
authors: CJ
authors: Benmore
authors: Department of Physics, AlbaNova University Center, Stockholm University, SE-106 91 Stockholm, Sweden.
authors: Anders
authors: A
authors: Nilsson
authors: Department of Physics, AlbaNova University Center, Stockholm University, SE-106 91 Stockholm, Sweden.
authors: Lars G M
authors: LG
authors: Pettersson