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

Abstract

Solid-state ⁷⁷Se NMR measurements, first-principles molecular dynamics and DFT calculations of NMR parameters were performed to gain insight into the structure of selenium-rich Ge_xSe_(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 ⁷⁷Se NMR spectra calculated on the basis of the structural models deduced from these simulations are consistent with the experimental spectrum.