Speaker: Lars G.M. Pettersson (Department of Physics, Stockholm University)
Title: A Two-State Picture of Water and Possible Consequences
Abstract: I will describe the picture of normal liquid water as locally fluctuating between two classes of local structures, reminiscent of high- and low-density liquid (HDL and LDL). HDL and LDL can only exist as identifiable liquid phases in the so-called “No-man’s land” below the temperature of homogeneous ice nucleation (~232 K) and above the glass transition (~136 K) and then only transiently. I will use computed X-ray absorption (XAS) and emission (XES) spectra together with the experimental XAS, XES and OO pair-distribution function in a reverse Monte Carlo simulation to determine what structures exist in the liquid. I will investigate the dissolution of gases in water and suggest that, e.g., O2 will preferentially associate with more open LDL environments. This leads to the question how fish extract oxygen from water, i.e. how fish breathe.