A new monoclinic phase of indium phosphate dihydrate, InPO4. 2H(2)O, was pr
epared from a hydrothermal synthesis of H3PO4, In(OH)(3) and H2O in the pre
sence of HF and C7H13N (quinuclidine), The structure is isostructural with
AlPO4. 2H(2)O (metavariscite). The geometry of the H atoms in the title com
pound is consistent with that of metavariscite.