Density fluctuations in water are at the heart of numerous processes associated with hydrophobic effects. One of the most fundamental processes in this regard, is the work associated with the creation of holes or cavities in water. In most theoretical and simulation studies, the focus has been on the thermodynamics of the creation of spherical cavities or idealized shapes. Recently Sosso and co-workers used a Voronoi based analysis to characterize non-spherical and realistic shapes in liquid water at ambient conditions and found that the thermodynamics associated with their creation is qualitatively different. In this work, we characterize the void landscape across the pressure-temperature phase diagram of water using molecular dynamics simulations. Measures for the preference of specific shapes in water are discussed. We also characterize the lifetimes of the voids and how this changes with respect to both pressure and temperature. The implications of non-spherical and extended voids across the hydrogen bond network of water on the presence of patches of low-density and high-density liquid water will also be briefly discussed.
 GC Sosso et al, J. Phys. Chem. A 2017, 121, 370−380.