Co3(PO4)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted CoO5 trigonal bipyramids that share  a cornercorner with one Co(2)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one Co(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 61°. In the second Co site, Co(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form CoO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra, corners with two equivalent Co(1)O5 trigonal bipyramids, and edges with two equivalent Co(1)O5 trigonal bipyramids. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with three equivalent Co(2)O6 octahedra, corners with three equivalent Co(1)O5 trigonal bipyramids, and  an edgeedge with one Co(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 37-54°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Co(1), one Co(2), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Co(1), one Co(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Co(1), one Co(2), and one P(1) atom.
Co3(PO4)2 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Co sites. In the first Co site, Co(1) is bonded to one O(2), one O(3), one O(4), and two equivalent O(1) atoms to form distorted CoO5 trigonal bipyramids that share  a cornercorner with one Co(2)O6 octahedra, corners with three equivalent P(1)O4 tetrahedra,  an edgeedge with one Co(2)O6 octahedra,  an edgeedge with one P(1)O4 tetrahedra, and  an edgeedge with one Co(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles are 61°. The Co(1)-O(2) bond length is 2.25 Å. The Co(1)-O(3) bond length is 1.97 Å. The Co(1)-O(4) bond length is 2.01 Å. There is one shorter (1.97 Å) and one longer (2.00 Å) Co(1)-O(1) bond length. In the second Co site, Co(2) is bonded to two equivalent O(2), two equivalent O(3), and two equivalent O(4) atoms to form CoO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra, corners with two equivalent Co(1)O5 trigonal bipyramids, and edges with two equivalent Co(1)O5 trigonal bipyramids. Both Co(2)-O(2) bond lengths are 2.06 Å. Both Co(2)-O(3) bond lengths are 2.12 Å. Both Co(2)-O(4) bond lengths are 2.17 Å. P(1) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with three equivalent Co(2)O6 octahedra, corners with three equivalent Co(1)O5 trigonal bipyramids, and  an edgeedge with one Co(1)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 37-54°. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(2) bond length is 1.53 Å. The P(1)-O(3) bond length is 1.53 Å. The P(1)-O(4) bond length is 1.55 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to two equivalent Co(1) and one P(1) atom. In the second O site, O(2) is bonded in a distorted T-shaped geometry to one Co(1), one Co(2), and one P(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Co(1), one Co(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Co(1), one Co(2), and one P(1) atom.