Relation of vitron theory to 2-layer-liquid immiscibility in binary silicate and borate glass melts

Silica-rich and boron-rich binary glasses resemble c1athrates in having host cavities in which modifier oxides may be inclosed without stress as inactive gues ts until the cavities are approximately fill ed. Additional modification results in stress both in the holes of the matrix and the cavities of vitrons. Then the structur e begins to disintegrate and mixing takes place. The r equired mole-percent modification is expressed by an equation of the form