Scientists Just Confirmed The Existence of a New Crystalline Structure of Ice - ScienceAlert

When ice I is cooled in a certain way, the hydrogen atoms can periodically become ordered, in addition to the oxygen atoms.

This is how scientists in a lab can create different phases of ice that have much more ordered crystalline molecule lattices than their disordered parent forms.

Validating that the ice was a separate phase was a separate hurdle, requiring that the normal water be replaced with 'heavy' water.

Heavy water, on the other hand, is based on deuterium, a form of hydrogen that has one neutron in the nucleus.

In order to figure the ordering of atoms in a crystal lattice, scientists need to scatter neutrons from nuclei, so normal hydrogen atoms won't cut it.

This makes the pair sibling phases - the first known that have the same oxygen lattice structure, but with differing arrangements of hydrogen atoms.