![]() These results open new perspectives to understand the dynamics of supercooled water and show the performance of the TIP4P/2005f force field to characterize it. It compares well with three databases available in the literature, and its application procedure is also simpler than other previously developed correlations. In particular, deviations from the Stokes–Einstein relation appear at lower temperatures for the viscosity than for the α-relaxation time. An empirical formula is proposed for the calculation of the viscosity of glycerolwater mixture for mass concentrations in the range of 0100 and temperatures varying from 0 to 100 ☌. Water has a viscosity of 0. Unlike what is usually admitted, our tests suggest those quantities are not coupled at low temperatures, and thus should not be considered equivalent. The dynamic viscosity of water is 8.90 × 10 4 Pa·s or 8.90 × 10 3 dyn·s/cm 2 or 0.890 cP at about 25 ☌. By computing shear viscosity over this domain, we compare the accuracy of several phenomenological laws for low temperature dynamics of water to describe both viscosity and α-relaxation time. 350 K, suggesting a supercooled-like dynamics over a very large domain of temperatures. Focusing first on the structural relaxation dynamics, we observe a decoupling between the so-called α- and β-relaxation times of water at ca. We show that the TIP4P/2005f model reproduces accurately the experimental values of both the viscosity and the diffusion coefficient over a very large range of temperatures. Here we used molecular dynamics simulations with the promising TIP4P/2005f water force field to investigate the behavior of both the shear viscosity and the relaxation times of water in a large range of temperatures, in order to get a consistent picture of the dynamics of supercooled water. Previously the viscosity was given in poises (or centipoises, 1 cP 1 mPas). ![]() Moreover, recent work showed that viscosity and relaxation times could decouple at low temperature in a model binary mixture, raising questions on their equivalence to study supercooled water. During the last few decades, many experimental and numerical studies have tried to understand the special dynamics of water at low temperatures by measuring structural relaxation times or shear viscosity, but their conclusions strongly depended on the chosen observable and on the range of temperatures considered.
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