Planewave DFT calculations of the shielding and quadrupolar tensors provided a helpful starting point for spectral fitting. Full (CT and ST) simulations of the experimental lineshape yielded a In quadrupolar coupling constant of 54.5 (10) MHz with an asymmetry of 0.53(2) (Table MHz]. Nevertheless, the experimental In C Q in the quaternary oxide is substantially larger than the DFT-predicted value. A similar phenomenon was observed for 121 Sb. The intermediate In and 121 Sb asymmetry parameters are consistent with the lack of axial symmetry at the indium or antimony site.