2013/02/28 by Vincent Holten, David T. Limmer, Valeria Molinero +2 · 140 citations
Earth and Planetary Sciences · Engineering · Materials Science · Physics and Astronomy · #Computer science #Environmental science #Liquid state #Liquid water #Material Dynamics and Properties #Materials science #Phase Equilibria and Thermodynamics #Physics #State (computer science) #Supercooling #Thermodynamics #cond-mat.stat-mech #nanoparticles nucleation surface interactions #physics.chem-ph
paper · pdf · doi:10.1063/1.4802992
published in The Journal of Chemical Physics 138(17), 174501 (American Institute of Physics) · 10 pages, 8 figures
arxiv created 2013/04/01 · openalex publication_date 2013/05/01 · arxiv updated 2013/05/02 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The thermodynamic properties of the supercooled liquid state of the mW model of water show anomalous behavior. Like in real water, the heat capacity and compressibility sharply increase upon supercooling. One of the possible explanations of these anomalies, the existence of a second (liquid-liquid) critical point, is not supported by simulations for this model. In this work, we reproduce the anomalies of the mW model with two thermodynamic scenarios: one based on a non-ideal "mixture" with two different types of local order of the water molecules, and one based on weak crystallization theory. We show that both descriptions accurately reproduce the model's basic thermodynamic properties. However, the coupling constant required for the power laws implied by weak crystallization theory is too large relative to the regular backgrounds, contradicting assumptions of weak crystallization theory. Fluctuation corrections outside the scope of this work would be necessary to fit the forms predicted by weak crystallization theory. For the two-state approach, the direct computation of the low-density fraction of molecules in the mW model is in agreement with the prediction of the phenomenological equation of state. The non-ideality of the "mixture" of the two states never becomes strong enough to cause liquid-liquid phase separation, also in agreement with simulation results.