Unravelling the contribution of local structures to the anomalies of water: the synergistic action of several factors

Abstract

We investigate the microscopic origin of water's anomalies by inspecting the hydrogen bond network (HBN) and the spatial organization of low-density-liquid (LDL) like and high-density-liquid (HDL) like environments. Specifically, we simulate --via classical molecular dynamics simulations-- the isobaric cooling of a sample composed by 512 water molecules from ambient to deeply undercooled conditions at three pressures, namely 1 bar, 400 bar and 1000 bar. \emph{In correspondence with the Widom line}, (i) the HDL-like dominating cluster undergoes fragmentation caused by the percolation of LDL-like aggregates following a spinodal-like kinetics; (ii) such fragmentation always occur s at a "critical" concentration of $\sim 20-30\%$ in LDL; (iii) the HBN within LDL-like environments is characterized by an equal number of pentagonal and hexagonal rings that create a state of maximal frustration between a configuration that promotes crystallization (hexagonal ring) and a configuration that hinders it (pentagonal ring); (iv) the spatial organization of HDL-like environments shows a marked variation. Moreover, the inspection of the global symmetry shows that the intermediate-range order decreases in correspondence with the Wid om line, and such decrease becomes more pronounced upon increasing the pressure, hence supporting the hypothesis of a liquid-liquid critical point. Our results reveal and rationalize the complex microscopic origin of water's anomalies as the cooperative effect of several fac tors acting synergistically. Beyond implications for water, our findings may be extended to other materials displaying anomalous behaviours.

References in corpus (5)

• Mixture-like behavior near a liquid-liquid phase transition in simulations of supercooled water
• Thermodynamics of Fluid Polyamorphism
• Large-scale structure and hyperuniformity of amorphous ices
• Structural Properties of High and Low Density Water in a Supercooled Aqueous Solution of Salt
• Potential Energy Landscape of the Apparent First-Order Phase Transition between Low-Density and High-Density Amorphous Ice

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• A water structure indicator suitable for generic contexts: two-liquid behavior at hydration and nanoconfinement conditions and a molecular approach to hydrophobicity and wetting
• Synergism of the dynamics of tetrahedral hydrogen bonds of liquid water
• Molecular aggregation in liquid water: Laplace spectra and spectral clustering of H-bonded network
• Manifestations of the structural origin of supercooled water's anomalies in the heterogeneous relaxation on the potential energy landscape
• Hydrogen Bond Topology Reveals Layering of LDL-like and HDL-like Water at its Liquid/Vapor Interface
• Machine learning evaluation of structural descriptors for supercooled water
• Memory Control of Ice Growth During Non-Equilibrium Freezing of Water