Variable temperature non-spinning Li NMR spectroscopy was undertaken to investigate the Li ion dynamic behavior in these compounds. Figure shows the Li NMR spectra obtained between 203 and 333 K. The changes in linewidth, nuclear spin-lattice relaxation and chemical shift are reported in Table . At room temperature, the Li NMR linewidths are 0.7 to 1.5 kHz across the series, with Bi-rich materials being narrower (faster Li ion dynamics) than Sb-rich sister compounds. All compounds exhibit decreasing linewidths with increasing temperature.