A combined 77Se NMR and molecular dynamics contribution to the structural understanding of the chalcogenide glasses

Solid-state Se-77 NMR measurements, first-principles molecular dynamics and DFT calculations of NMR parameters were performed to gain insight into the structure of selenium-rich GexSe(1-x) glasses. We recorded the fully-relaxed NMR spectra on natural abundance and 100% isotopically enriched GeSe4 samples, which led us to reconsider the level of structural heterogeneity in this material. In this paper, we propose an alternative procedure to initialise molecular dynamics runs for the chalcogenide glasses. The Se-77 NMR spectra calculated on the basis of the structural models deduced from these simulations are consistent with the experimental spectrum.