Water is one of the most common and extensively studied substances on earth. It is vital for all known forms of life but its unique behaviour has yet to be explained in terms of the properties of individual molecules.
Water derives many of its signature features from a combination of
properties at the molecular level such as high polarizability,
directional hydrogen bonding sites and van der Waals forces, the
attractive or repulsive forces between molecules not related to covalent
or ionic bonds.
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| 2D plot of extended structure in electronically coarse grained liquid water showing angular correlations (vertical axis) vs oxygen distance (horizontal axis). The peaks (yellow and red regions) are indicative of an extended hydrogen bonding network - a signature feature of liquid water. The inset shows the strong electronic polarization of the water molecule that occurs in the liquid where red and blue represent regions of enhanced and depleted electron density. (Credit: Image courtesy of National Physical Laboratory) |