Structure of water – the full pair correlation function

structure of water (367 kB) Bunches of red oxygens and white hydrogens show the probability that a water molecule at certain distance r from the fixed (blue and yellow) molecule will have given relative position and orientation. The animation is thus an attempt to visualize the full pair correlation function. This function is six-dimensional: one distance r and five angular variables. We have measured this function during a 300 ps simulation of 500 TIP4P water molecules at T=25oC and ambient density. O-O correlation function The histograms were taken by 15o in each angular variable (with the exception of regions close to the poles). The r-coordinate is identified with time, i.e., each frame corresponds to a selected distance (shown in red in the graph of the O-O pair correlation function). For this distance, one molecule from the pair is fixed, and around it 8000 positions of water molecules with highest probability are drawn with diameters proportional to the probability. See also the water page.