Crystal structure of the Anderson-type heteropolyoxometalate; K<sub>2</sub>[H<sub>7</sub>Cr<sup>III</sup>Mo<sub>6</sub>O<sub>24</sub>]·8H<sub>2</sub>O: a redetermination revealing the position of the extra H atom in the polyanion
Acta crystallographica. Section E, Crystallographic communications