Short-Range and Medium-Range Order in Lithium Silicate Glasses, Part II: Simulation of the Structure by the Reverse Monte Carlo Method

The results of X-ray and neutron diffraction experiments with (Li₂O) _x (SiO₂)_{100_x} glasses (x = 0, 20, 33.3, and 40) are discussed using the Reverse Monte Carlo method to produce atomic clusters, which are analyzed with respect to the O-O distribution, the angular correlations within the first and higher coordination spheres, and the bond-orientational multipole moments. Within Li₂O-containing silicate glasses, each lithium atom is surrounded by a ring of six SiO₄ tetrahedra in such a way that four oxygen atoms lie at the joints of a tetragonal cell centered by lithium. Thus, the lithium atoms increase the order of the glass.