Co(3)(PO(4))(2)·4H(2)O

Single crystals of Co(3)(PO(4))(2)·4H(2)O, tricobalt(II) bis­[ortho­phosphate(V)] tetra­hydrate, were obtained under hydro­thermal conditions. The title compound is isotypic with its zinc analogue Zn(3)(PO(4))(2)·4H(2)O (mineral name hopeite) and contains two independent Co(2+) cations. One Co(2+) cation exhibits a slightly distorted tetra­hedral coordination, while the second, located on a mirror plane, has a distorted octa­hedral coordination environment. The tetra­hedrally coordinated Co(2+) is bonded to four O atoms of four PO(4) (3−) anions, whereas the six-coordinate Co(2+) is cis-bonded to two phosphate groups and to four O atoms of four water mol­ecules (two of which are located on mirror planes), forming a framework structure. In addition, hydrogen bonds of the type O—H⋯O are present throughout the crystal structure.