Structural Properties of Water by a Flexible Water Model

The structural properties of water at different temperatures have been investigated using a flexible water model in the isothermal-isobaric ensemble. With decreasing temperature, the tetrahedrality of the distribution of the water molecules around the central water molecule is enhanced, and the hydrogen bonds become more linear. By means of a conjugate gradient energy minimization, dynamical configurations at various temperatures have been mapped onto nearby potential-energy minima, the 50°-60°peak (P₁) in the distribution function of the O-O-O angle of a trimer becomes far smaller. However there appears to be a small but observable temperature dependence of P₁, i.e., the higher the temperature, the higher the P₁ intensity.