We propose that the defect-ordered nature of the crystal structure can reconcile this unusual photophysical behavior. Collectively, PL and TRMC data are consistent with localized defect-like states accessible with band-to-band excitation that have a high oscillator strength and rapid non-radiative recombination rates. Such flat bands with charge density on [SnI 5 ] polyhedra are visible in the electronic structure calculations. These states may also yield a low conversion to mobile charge carriers (e.g., Φ < 1), further reducing the mobility assessed from TRMC. The photoluminescence is more consistent with single-ion behavior characteristic of ns 2 electron configurations. For example, the vacancy-ordered double perovskite Rb 2 TeBr 6 exhibits deep-red luminescence (680 nm) with excitation into the UV (bands at 485 nm, 410 nm, and 350 nm). The large Stokes shift has been attributed to the dynamic Jahn-Teller distortions of the 3 P derived excited states of the single ions. Further studies on other ATeX 6 compounds with asymmetric A-site cations reveal that distortion of the octahedron can further increase the Stokes shift, consistent with the presence of [SnI 5 ] polyhedra. These single-ion excited states may yield long lifetimes (relative to the non-radiative recombination) but low conversion rates to mobile charge carries, thus also being consistent with the TRMC experiments with 355 nm excitation.