The 31P NMR chemical shielding tensors in quaternary metal thiophosphates, NaNb2PS10, AgNb2PS10, Au0.5Nb2PS10, and NaSmP2S6

Abstract

For quaternary metal thiophosphates, NaNb2PS10, AgNb2PS10, and NaSmP2S6, the principal elements of the 31P NMR chemical shielding tensor (δ11, δ22, δ33) are acquired from the nonlinear least-squares fitting the static powder patterns and MAS spectra. Isotropic chemical shift (δiso) and chemical shielding anisotropy (Δδ) have been employed to correlate with the X-ray crystallographic data, the average (P-S) bond length and the average (S-P-S) bond angle deviation from 109.5°, respectively, at the tetrahedrally coordinated phosphorus atoms. On the basis of these successful correlations, the charge transfer from Na, Ag, and Au metals to the (P-S) ligand is discussed and complemented by the band-structure calculation.