Both the unit cell volume and Li chemical shift show the largest deviation from a linear trend between Li3Bi and Li3Sb at xSb = 0.25. The asymmetric resonance for Li3Sb0.25Bi0.75 appears to be composed of two peaks where a minor higher frequency edge is Sb-rich with a similar chemical shift to the Li3Sb0.5Bi0.5 composition (Figure , inset), that remains post-annealing. Li3Sb0.5Bi0.5 and Li3Sb0.75Bi0.25 exhibit Gaussian-like lineshapes with minor broadening observed for the Sbrich phase at the base of the Li NMR spectrum which is attributed to a reduction in long-range order (ball milling). This result indicates some local variations in the Sb/Bi ratios. Such incipient phase segregation may be due to the differences in Li affinity between Sb and Bi as reflected by their different plateau voltages in electrochemical experiments, as was discussed earlier.