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A common approach to quantify Q⁽ⁿ⁾ species in silicate glasses is to use ²⁹Si magic-angle spinning (MAS) nuclear magnetic resonance (NMR) and assume that the overlapping isotropic chemical shift distributions of Q⁽ⁿ⁾ species are Gaussian. We have shown that a two-dimensional isotropic/anisotropic ²⁹Si NMR experiment can not only determine the distributions of Q⁽ⁿ⁾ species without any a priori assumptions about the distribution, but can also provide over an order of magnitude improvement in the precision of Q⁽ⁿ⁾ species quantification in silicate glasses. Using this approach we have investigated an alkali silicate glass of composition 2Na₂O · 3SiO₂ and have observed a small concentration of Q⁽⁴⁾ in a sample mainly having Q⁽²⁾ and Q⁽³⁾. We have found that the distribution of isotropic chemical shifts for each of the Q⁽ⁿ⁾ is approximately Gaussian. The relative populations of Q⁽²⁾, Q⁽³⁾, and Q⁽⁴⁾ obtained …