Figure 1
Polyoxometalate clusters in minerals shown in polyhedral (left) and skeletal (right) representations: the [Nb6O19]8− cluster in melcherite (a), the [V10O28]6− cluster in pascoite (b), the [AsV12O40(VO)]12− cluster in kegginite (c), and the [H2PV5+12O40(V5+O)2]7− cluster in bicapite (d). |