It has recently been shown that the TIP4P/Ice model of water can be studied numerically in metastable equilibrium at and below its liquid– liquid critical temperature. We report here simulations along a subcritical isotherm, for which two liquid states with the same pressure and temperature but different density can be equilibrated. This allows for a clear visualization of the structural changes taking place across the transition. We specifically focus on how the topological properties of the H-bond network change across the liquid–liquid transition. Our results demonstrate that the structure of the high-density liquid, characterized by the existence of interstitial molecules and commonly explained in terms of the collapse of the second neighbor shell, actually originates from the folding back of long rings, bringing pairs of molecules separated by several hydrogen-bonds close by in space.

Structural and topological changes across the liquid - liquid transition in water / Foffi, Riccardo; Russo, John; Sciortino, Francesco. - In: THE JOURNAL OF CHEMICAL PHYSICS. - ISSN 0021-9606. - 154:18(2021). [10.1063/5.0049299]

Structural and topological changes across the liquid - liquid transition in water

Riccardo Foffi;John Russo;Francesco Sciortino
2021

Abstract

It has recently been shown that the TIP4P/Ice model of water can be studied numerically in metastable equilibrium at and below its liquid– liquid critical temperature. We report here simulations along a subcritical isotherm, for which two liquid states with the same pressure and temperature but different density can be equilibrated. This allows for a clear visualization of the structural changes taking place across the transition. We specifically focus on how the topological properties of the H-bond network change across the liquid–liquid transition. Our results demonstrate that the structure of the high-density liquid, characterized by the existence of interstitial molecules and commonly explained in terms of the collapse of the second neighbor shell, actually originates from the folding back of long rings, bringing pairs of molecules separated by several hydrogen-bonds close by in space.
2021
supercooled water, molecular dynamic simulation, liquid-liquid transition
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Structural and topological changes across the liquid - liquid transition in water / Foffi, Riccardo; Russo, John; Sciortino, Francesco. - In: THE JOURNAL OF CHEMICAL PHYSICS. - ISSN 0021-9606. - 154:18(2021). [10.1063/5.0049299]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11573/1556078
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