Thermodynamic and Structural Characteristics of SPC/E Water at 290 K and under High Pressure

Large SPC/E water models are studied by the Monte Carlo method in a wide range of pressures (1 bar-17.5 kbar) at a temperature of 290 K. Pressure dependences of density, specific heat (c(P)), isothermal compressibility, volumetric thermal expansion coefficient, and dielectric constant of water are calculated. The main structural elements of the coordination shells of water molecules are studied by analysing radial and spatial distribution functions of oxygen and hydrogen atoms. It is suggested to separate the molecules of the first coordination shell into geometrical and topological neighbors of different orders depending on the length of the chain of hydrogen bonds between them. It is shown that most geometrical neighbors are second-order topological neighbors under normal conditions and are mainly higher-order neighbors under higher pressures.