Structures with unconnected PO4 groups

Phosphate minerals of this class are listed in Table 5. In these minerals, the (PO4) groups and octahedra are linked together by hydrogen bonding. 

In struvite, [Mg(H20)6][P04], the (PO4) tetrahedra and (Mg H20 6) octahedra are linked solely by hydrogen bonding from the (H2O) groups bonded to Mg directly to the anions of the (PO4) groups, or by hydrogen bonding from the interstitial (NH4) group 

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