The determination of the crystal structure of the title compound, tria
mmonium triacontaoxo(tetraoxophosphato)dodecamolybdate(3-) henicosahyd
rate, shows that the polyanion has a pseudo-Keggin structure with m (3
) over bar m symmetry. The central PO4 group is disordered with P-O di
stances of 1.55 (3) Angstrom. The Mo-O distances range from 1.617 (14)
to 2.414 (14) Angstrom.