Computational simulations of solid state NMRspectra: a new era in structure determination of oxide glasses

Abstract

The application of the MD–GIPAW approach to the calculation of NMR parameters, line widths and shapes of the spectra of oxide glasses is reviewed. Emphasis is given to the decisive role of this approach both as an interpretative tool for a deeper understanding of the spectral behavior of complex systems and as a predictive instrument to map NMR data in a distribution of structural parameters and vice versa (structural inversion method). After a brief overview of the basic features of oxide glasses and the experimental techniques routinely employed to investigate their structure, a general description of the computational methods usually adopted to generate sound structural models of amorphous materials is offered. The computational recipe used to compute the solid state NMR spectra of oxide glasses and to establish quantitative structural-NMR property relationships is then described. Finally, these concepts are applied to ‘simple’ network former glasses and more complex silicates, aluminosilicate, phosphosilicate and borosilicate glasses of scientific relevance. The final section is dedicated to the future developments that will hopefully improve the computational approach described overcoming some of the current limitations.