KMg6(P2O7)2P3O10: A novel phosphate with two distinct anions

Two kinds of isolated polyphosphate anions, [P2O7] clusters and [P3O10] clusters, coexist in the phosphate KMg6(P2O7)2P3O10, which crystallizes in the monoclinic space group P21/m. Such coexisting of two distinct anions in one polyphosphate, which has somewhat conflict with Pauling's parsimony (V) rule, is very rare in alkali metal and alkali-earth metal phosphates. Discovery of this compound enriches the structural chemistry of phosphates and may provide new perspective on the design of multiple anion materials.