One-dimensional ²⁷Al, ²³Na Magic-Angle-Spinning (MAS) NMR and ²⁷Al Multiple-Quantum Magic-Angle-Spinning NMR (MQMAS) measurements are reported for the δ-isomer of the Al₁₃ Keggin structure at high spinning speed and 14.1 T field. Values for the C_Q and η parameters are on the same scale as those seen in other isomers of the Al₁₃ structure. Density functional theory (DFT) calculations are performed for comparison to the experimental fits using the B3PW91/6-31+G* and PBE0/6-31+G* levels of theory, with the Polarizable Continuum Model (PCM).