Two-state thermodynamics of the ST2 model for supercooled water

Vincent Holten, Jeremy C. Palmer, Peter H. Poole, Pablo G. Debenedetti, Mikhail A. Anisimov

Research output: Contribution to journalArticle

55 Scopus citations

Abstract

Thermodynamic properties of the ST2 model for supercooled liquid water exhibit anomalies similar to those observed in real water. A possible explanation of these anomalies is the existence of a metastable, liquid-liquid transition terminated by a critical point. This phenomenon, whose possible existence in real water is the subject of much current experimental work, has been unambiguously demonstrated for this particular model by most recent simulations. In this work, we reproduce the anomalies of two versions of the ST2 model with an equation of state describing water as a non-ideal "mixture" of two different types of local molecular order. We show that the liquid-liquid transition in the ST2 water is energy-driven. This is in contrast to another popular model, mW, in which non-ideality in mixing of two alternative local molecular orders is entropy-driven, and is not sufficiently strong to induce a liquid-liquid transition.

Original languageEnglish (US)
Article number104502
JournalJournal of Chemical Physics
Volume140
Issue number10
DOIs
StatePublished - Mar 14 2014

All Science Journal Classification (ASJC) codes

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Two-state thermodynamics of the ST2 model for supercooled water'. Together they form a unique fingerprint.

  • Cite this