Lindemann's rule applied to the melting of crystals and ultra-stable glasses

The Lindemann constants δls at the melting temperature Tm (N° 1 & 2) and δlg at the glass transition temperature Tg (N° 3 & 4) of 23 metallic and 49 non-metallic glasses are plotted versus θg = (Tg − Tm)/Tm. In pure metallic liquid elements, δls = 0.103, δlg = 0.05 & θg = −0.6223.