29Si NMR spectroscopy of silica glass: T1 relaxation and constraints on the Si–O–Si bond angle distribution

A 29Si NMR spectrum with high signal to noise ratio was collected from a well-characterized, isotopically-enriched SiO2 glass with a single scan after full relaxation of the magnetization. From the spectrum, the average Si–O–Si bond angle was estimated at 150° with a minimum fwhm of the bond angle distribution of 16°. The 29Si spin-lattice relaxation times were measured by saturation recovery and differential T1 relaxation was observed for the various Si environments.