In contrast to the abundance of studies on water at positive pressure, the behavior of water at negative pressure remains relatively unexplored. We employed large-scale molecular dynamics simulations to investigate the thermodynamic behavior of the TIP4P/2005 water model at deeply stretched (large negative pressure) conditions. We find that isochores without a pressure minimum can display “reentrant” behavior --- system cavitates upon cooling and then spontaneously rehomogenizes upon further cooling. This behavior is a consequence of the underlying density maximum along the vapor-liquid spinodal. This observation suggests that propensity toward cavitation does not always correlate with greater tension, contrary to the common assumption for interpreting the results in water stretching experiments. We also observe that a maximum vapor-liquid spinodal density in water gives rise to a locus of maximum isothermal compressibility and a minimum speed of sound that are independent from any influence of a liquid-liquid critical point. We anticipate that any liquid with water-like density anomaly (e.g. silicon and germanium) should display reentrant behavior and spinodal-induced extrema in thermodynamic response functions.<br/>

Thermodynamic anomalies in deeply stretched water

256th National Meeting (2018)

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