The solid solution Na0.39(NH4)1.61SO4·Te(OH)6

The title compound, sodium ammonium sulfate–telluric acid (1/1), Na0.39(NH4)1.61SO4·Te(OH)6, is isostructural with other solid solutions in the series M1−x(NH4)xSO4·Te(OH)6, where ammonium is partially replaced with an alkali metal (M = K, Rb or Cs). The structure is composed of planes of Te(OH)6 octa­hedra alternating with planes of SO4 tetra­hedra. The Na+/NH4+ cations are statistically distributed over the same position and are located between the planes. The structure is stabilized by O—H⋯O and N—H⋯O hydrogen bonds between the telluric acid adducts and the O atoms of sulfate groups, and between the ammonium cations and O atoms, respectively. Both Te atoms lie on centres of symmetry.