Determining melting temperatures without solid insight

We report the discovery of a distinctive, universal signature in atomic motions within the liquid phase that signals the onset of freezing—independent of the specific interatomic forces at play.

This finding gives a microscopic basis of the thermodynamic freezing point, ofering fresh insight into the liquid-solid phase transition. Importantly, this incipient freezing signature can be directly extracted from molecular dynamics simulations, enabling accurate determination of melting curves. Unlike conventional approaches, our method requires no prior knowledge of the crystalline solid phase into whichthe material eventually freezes—a key advantage, especially under extreme conditions where the stable solid structure is unknown or experimentally inaccessible. In this talk, we will discuss the microscopic nature of freezing and showcase results that demonstrate the efectiveness and applicability of this solid-agnostic approach to mapping melting lines (LA-UR-25-23269).