https://doi.org/10.1140/epje/i2011-11048-1
Quantitative investigation of the two-state picture for water in the normal liquid and the supercooled regime
1
Sección Fisicoquımica - INQUISUR and Departamento de Quımica, Universidad Nacional del Sur, Avenida Alem 1253, 8000, Bahıa Blanca, Argentina
2
Dipartimento di Fisica and CNR-ISC, Università di Roma La Sapienza, Piazzale A. Moro 2, 00185, Roma, Italy
* e-mail: rodriguezfris@plapiqui.edu.ar
Received:
21
December
2010
Revised:
19
March
2011
Accepted:
6
April
2011
Published online:
16
May
2011
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.
© EDP Sciences, SIF, Springer-Verlag Berlin Heidelberg, 2011
