Effect of hydrogen bond cooperativity on the behavior of water

Four scenarios have been proposed for the low--temperature phase behavior of liquid water, each predicting different thermodynamics. The physical mechanism which leads to each is debated. Moreover, it is still unclear which of the scenarios best describes water, as there is no definitive experimenta...

Full description

Saved in:
Bibliographic Details
Published inarXiv.org
Main Authors Stokely, Kevin, Mazza, Marco G, Stanley, H Eugene, Franzese, Giancarlo
Format Paper
LanguageEnglish
Published Ithaca Cornell University Library, arXiv.org 27.08.2009
Subjects
Computer simulation
Critical point
Hydrogen bonds
Mathematical models
Phase diagrams
Water
Online AccessGet full text

Cover

More Information
Summary:Four scenarios have been proposed for the low--temperature phase behavior of liquid water, each predicting different thermodynamics. The physical mechanism which leads to each is debated. Moreover, it is still unclear which of the scenarios best describes water, as there is no definitive experimental test. Here we address both open issues within the framework of a microscopic cell model by performing a study combining mean field calculations and Monte Carlo simulations. We show that a common physical mechanism underlies each of the four scenarios, and that two key physical quantities determine which of the four scenarios describes water: (i) the strength of the directional component of the hydrogen bond and (ii) the strength of the cooperative component of the hydrogen bond. The four scenarios may be mapped in the space of these two quantities. We argue that our conclusions are model-independent. Using estimates from experimental data for H bond properties the model predicts that the low-temperature phase diagram of water exhibits a liquid--liquid critical point at positive pressure.
ISSN:2331-8422