title: Quantitative investigation of the two-state picture for water in the normal liquid and the supercooled regime.
abstract: Several evidences have helped to establish the two-state nature of liquid water. Thus, within the normal liquid and supercooled regimes water has been shown to consist of a mixture of well-structured, low-density molecules and unstructured, high-density ones. However, quantitative analyses have faced the burden of unambiguously determining both the presence and the fraction of each kind of water "species". A recent approach by combining a local structure index with potential-energy minimisations allows us to overcome this difficulty. Thus, in this work we extend such study and employ it to quantitatively determine the fraction of structured molecules as a function of temperature for different densities. This enables us to validate predictions of two-state models.
authors.affiliation: Sección Fisicoquımica - INQUISUR and Departamento de Quımica, Universidad Nacional del Sur, Avenida Alem, Bahıa Blanca, Argentina.
authors.forename: S R
authors.initials: SR
authors.lastname: Accordino
authors.forename: J A
authors.initials: JA
authors.lastname: Rodriguez Fris
authors.forename: F
authors.initials: F
authors.lastname: Sciortino
authors.forename: G A
authors.initials: GA
authors.lastname: Appignanesi
mesh_terms: D001703:Biophysics / Q000379:methods*; D003080:Cold Temperature; D006860:Hydrogen Bonding; D008956:Models, Chemical; D012996:Solutions / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry*; D014867:Water / Q000032:analysis* / Q000737:chemistry
chemical_list: D012996:Solutions; D012997:Solvents; D014867:Water