BaCo2(PO4)2 crystallizes in the trigonal P-3 space group. Ba(1) is bonded to six equivalent O(1) atoms to form BaO6 octahedra that share corners with six equivalent Co(1)O4 tetrahedra and corners with six equivalent P(1)O4 tetrahedra. Co(1) is bonded to one O(2) and three equivalent O(1) atoms to form CoO4 tetrahedra that share corners with three equivalent Ba(1)O6 octahedra and corners with four equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 67°. P(1) is bonded to one O(2) and three equivalent O(1) atoms to form PO4 tetrahedra that share corners with three equivalent Ba(1)O6 octahedra and corners with four equivalent Co(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ba(1), one Co(1), and one P(1) atom. In the second O site, O(2) is bonded in a linear geometry to one Co(1) and one P(1) atom.
BaCo2(PO4)2 crystallizes in the trigonal P-3 space group. Ba(1) is bonded to six equivalent O(1) atoms to form BaO6 octahedra that share corners with six equivalent Co(1)O4 tetrahedra and corners with six equivalent P(1)O4 tetrahedra. All Ba(1)-O(1) bond lengths are 2.80 Å. Co(1) is bonded to one O(2) and three equivalent O(1) atoms to form CoO4 tetrahedra that share corners with three equivalent Ba(1)O6 octahedra and corners with four equivalent P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 67°. The Co(1)-O(2) bond length is 1.91 Å. All Co(1)-O(1) bond lengths are 1.99 Å. P(1) is bonded to one O(2) and three equivalent O(1) atoms to form PO4 tetrahedra that share corners with three equivalent Ba(1)O6 octahedra and corners with four equivalent Co(1)O4 tetrahedra. The corner-sharing octahedral tilt angles are 61°. The P(1)-O(2) bond length is 1.52 Å. All P(1)-O(1) bond lengths are 1.57 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal planar geometry to one Ba(1), one Co(1), and one P(1) atom. In the second O site, O(2) is bonded in a linear geometry to one Co(1) and one P(1) atom.