Structure analysis of MgSiO3 glass

The structure of MgSiO₃ glass was investigated by a combination of radial distribution function (RDF) analysis with an intensity comparison method on the basis of X-ray diffraction data. There appeared five peaks at 1.63, 2.08, 2.58, 3.25 and 4.2 Å in the RDF curve. The short range structure was found to be similar to that observed in pyroxenes: single chains composed of SiO₄ tetrahedra are linked by Mg²⁺ ions laterally. The Mg²⁺ ion is surrounded by six oxygen atoms on average, four of which form MgO pairs with an average distance of 2.08 Å and the remainder Mg O pairs of 2.5 Å which contribute to the formation of the third peak at 2.58 Å in the RDF curve together with the OO pairs (2.66 Å) in SiO₄ tetrahedra. The calculated intensity curve based on this model was in good agreement with the observed one.