Glasses are amorphous solids, which are usually fabricated when the molten material cools very rapidly to below its glass transition temperature, without sufficient time for a regular crystal lattice to form. Solids are characterised by a high degree of connectivity between their molecules, and fluids have lower connectivity of their structural blocks. Melting of a solid material can also be considered as a percolation via broken connections between particles e.g. connecting bonds. In this approach melting of an amorphous material occurs, when the broken bonds form a percolation cluster with T g dependent on quasi-equilibrium thermodynamic parameters of bonds e.g. on enthalpy (H d) and entropy (S d) of formation of bonds in a given system at given conditions: