Two novel Mo(V) and Mo(V)/Mo(VI) barium phosphates with a tunnel structure: β-Ba(MoO)2(P2O7)2, and Ba(MoO)2O(P2O7)PO4

Projection of the crustal structures of (a) Ba(MoO)2O(P2O7)PO4 and of (b) Ba(MoO)2(P2O7)2 showing tunnels, containing Ba cations, and running through the frameworks.