The structure of K3MnO4CrO4

Abstract The mixed salt K 3 MnO 4 CrO 4 is isostructural with Sr 3 (PO 4 ) 2 although the former belongs to the non-centrosymmetric space group R 3 m and the latter to the centrosymmetric space group R [unk] m . The lattice parameters are a a rh = 7.8 ± 0.1 Å, α = 43° 10′ ± 30′. The structure has been refined, using the h 0· l reflections only, to a residual of 0.12. The average K–O distance is 2.93 ± 0.08 Å for two of the potassium atoms having ten nearest neighbours. The remaining potassium atoms have only six nearest neighbours at an average distance of 2.74 ± 0.08 Å.