Structural investigations of magnesium silicate glasses by 29Si 2D Magic-Angle Flipping NMR

► We quantify silicon with varying coordination for two magnesium silicate glasses. ► We examine how different modifying cations change the magnitude of the CSA. ► We apply the relative abundance of each Q(n)-species to known thermodynamic models. ► We compare calculated equilibrium constants to previous studies. ► We conclude that the disproportionation constant increases with cation potential.