Polyamorphism Mirrors Polymorphism in the Liquid-Liquid Transition of a Molecular Liquid.

Liquid-liquid transitions between two amorphous phases in a single-component liquid have courted controversy. All known examples of liquid-liquid transitions in molecular liquids have been observed in the supercooled state, suggesting an intimate connection with vitrification and locally favored structures inhibiting crystallization. However, there is precious little information about the local molecular packing in supercooled liquids, meaning that the order parameter of the transition is still unknown.