A relation doesn't exist.
When water freezes, the molecules are locked into place in a crystal structure, and it turns into a hard solid, or ice. The ice is hard because unlike in water, where the individual H2O molecules are free to move about and are not fixed in position, in ice each of the molecules is connected to the molecules next to it, making it hard. Freezing is a change of state of a material or substance, and it is a physical (not a chemical) change. We also need to mention that water expands when it freezes because of the formation of hydrogen bonds!
This question is similar to "How does linear motion function? With the exception of the planetary system, first it must be driven by power. When driven and no load applied to it, then its just an object in motion. In other words a motion without load or work whether it be rotation or linear motion does not serve a function.
- oxides are used as poison
- gallium arsenide is used in lasers in other electronic components
- hardening element in alloys of copper and lead
- component of pesticides
- medical uses (now in decline)
- war gases
- in stomatology to kill nerves
- anti-dezincification additive in brass
- preservation of biological samples