Water exhibits anomalous behavior in its supercooled region. A widely invoked hypothesis to explain supercooled water's thermodynamic anomalies is the existence of a metastable liquid-liquid transition terminating at a critical point. In this work, we analyze previously published and new simulation results for three commonly used molecular water models (ST2, TIP4P/2005, and TIP5P) that support the existence of the metastable liquid-liquid transition. We demonstrate that a corresponding-states-like rescaling of pressure and temperature results in a significant degree of universality in the pattern of extrema loci of the density, isothermal compressibility, and isobaric heat capacity. We also report, for the first time, an intriguing correlation between the location of the liquid-liquid critical point, the rescaled locus of density extrema, and the stability limit of the liquid state with respect to the vapor. A similar correlation is observed for two theoretical models that also exhibit a second (liquid-liquid) critical point, namely, the van der Waals and lattice-gas "two-structure" models. This new correlation is used to explore the stability limit of the liquid state in simultaneously supercooled and stretched water.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry