Ab initio study of NMR spectra of Li2S–SiS2 glass system

Abstract We obtained the chemical shielding constants of 29 Si in Li 2 S–SiS 2 glass system on the basis of molecular orbital calculations. The relative chemical shieldings calculated at the HF/6-31G* level is −16.1 and −23.8 ppm for E (1) and E (0), respectively. These calculations are in good agreement with the previous NMR study: σ ( E (2))> σ ( E (1))> σ ( E (0)). It is found theoretically that incorporation of Li 2 S into SiS 2 does not influence the 29 Si chemical shift, while incorporation of Li 2 O into SiO 2 does to a significant extent. It is also found that the existence of oxygen in Li 2 S–SiS 2 glasses increases the chemical shielding of 29 Si by about 25 ppm, which is in good agreement with the experimental result.