Figure 4.

Computed ${\hspace{0.17em}}^{17}\mathrm{O}$ MAS and 3QMAS spectra of sodium silicate (NS), calcium silicate (CS) and sodium calcium silicate (CSN) glasses. The spectra of the different O sites are highlighted in colour. The experimental ${\hspace{0.17em}}^{17}\mathrm{O}$ MAS spectra taken from the literature are also reported for specific compositions. Modifier cations surrounding BOs are reported in square brackets, while those surrounding NBOs are in parentheses. Reprinted with permission from [87]. Copyright (2012) American Chemical Society. (Online version in colour.)