Ba3(PO4)2 crystallizes in the trigonal R-3m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(2) and nine equivalent O(1) atoms. In the second Ba site, Ba(2) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form distorted BaO12 cuboctahedra that share edges with six equivalent Ba(2)O12 cuboctahedra and edges with six equivalent P(1)O4 tetrahedra. P(1) is bonded to one O(2) and three equivalent O(1) atoms to form PO4 tetrahedra that share edges with three equivalent Ba(2)O12 cuboctahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(2), three equivalent Ba(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1), three equivalent Ba(2), and one P(1) atom.
Ba3(PO4)2 crystallizes in the trigonal R-3m space group. There are two inequivalent Ba sites. In the first Ba site, Ba(1) is bonded in a 10-coordinate geometry to one O(2) and nine equivalent O(1) atoms. The Ba(1)-O(2) bond length is 2.67 Å. There are six shorter (2.87 Å) and three longer (2.92 Å) Ba(1)-O(1) bond lengths. In the second Ba site, Ba(2) is bonded to six equivalent O(1) and six equivalent O(2) atoms to form distorted BaO12 cuboctahedra that share edges with six equivalent Ba(2)O12 cuboctahedra and edges with six equivalent P(1)O4 tetrahedra. All Ba(2)-O(1) bond lengths are 2.76 Å. All Ba(2)-O(2) bond lengths are 3.25 Å. P(1) is bonded to one O(2) and three equivalent O(1) atoms to form PO4 tetrahedra that share edges with three equivalent Ba(2)O12 cuboctahedra. The P(1)-O(2) bond length is 1.53 Å. All P(1)-O(1) bond lengths are 1.55 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to one Ba(2), three equivalent Ba(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Ba(1), three equivalent Ba(2), and one P(1) atom.