2009/07/20 by M. M. Conde, Carlos Vega, Gareth A. Tribello +1 · 1 voice · 1 citation
Chemistry · Earth and Planetary Sciences · Environmental Science · Mathematics · #Arctic and Antarctic ice dynamics #Chemistry #Clathrate hydrate #Computational chemistry #Density functional theory #Diagram #Geology and Paleoclimatology Research #Hydrate #Ice Ih #Materials science #Mathematics #Methane Hydrates and Related Phenomena #Molecule #Phase (matter) #Phase boundary #Phase diagram #Physics #Thermodynamics
paper · doi:10.1063/1.3182727
openalex publication_date 2009/07/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/19
The phase diagram of water at negative pressures as obtained from computer simulations for two models of water, TIP4P/2005 and TIP5P is presented. Several solid structures with lower densities than ice Ih, so-called virtual ices, were considered as possible candidates to occupy the negative pressure region of the phase diagram of water. In particular the empty hydrate structures sI, sII, and sH and another, recently proposed, low-density ice structure. The relative stabilities of these structures at 0 K was determined using empirical water potentials and density functional theory calculations. By performing free energy calculations and Gibbs-Duhem integration the phase diagram of TIP4P/2005 was determined at negative pressures. The empty hydrates sII and sH appear to be the stable solid phases of water at negative pressures. The phase boundary between ice Ih and sII clathrate occurs at moderate negative pressures, while at large negative pressures sH becomes the most stable phase. This behavior is in reasonable agreement with what is observed in density functional theory calculations.