Role of structural changes at vitrification and glass–liquid transition

Structural rearrangements at calorimetric glass transition are behind drastic changes of material characteristics, causing differences between glasses and melts. Structural description of materials includes both species (atoms, molecules) and connecting bonds, which are directly affected by changing conditions such as the increase of temperature. At and above the glass transition a macroscopic percolation cluster made up of configurons (broken bonds) is formed, an account of which enables unambiguous structural differentiation of glasses from melts. Connection of transition caused by configuron percolation is also discussed in relation to the Noether theorem, Anderson localisation, and melting criteria of condensed matter.