Sr3(PO4)2 crystallizes in the trigonal R-3m space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to six equivalent O(2) atoms to form distorted SrO6 cuboctahedra that share corners with six equivalent P(1)O4 tetrahedra. In the second Sr site, Sr(2) is bonded in a 10-coordinate geometry to one O(1) and nine equivalent O(2) atoms. P(1) is bonded to one O(1) and three equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Sr(1)O6 cuboctahedra. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Sr(2) and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Sr(1), three equivalent Sr(2), and one P(1) atom.
Sr3(PO4)2 crystallizes in the trigonal R-3m space group. There are two inequivalent Sr sites. In the first Sr site, Sr(1) is bonded to six equivalent O(2) atoms to form distorted SrO6 cuboctahedra that share corners with six equivalent P(1)O4 tetrahedra. All Sr(1)-O(2) bond lengths are 2.58 Å. In the second Sr site, Sr(2) is bonded in a 10-coordinate geometry to one O(1) and nine equivalent O(2) atoms. The Sr(2)-O(1) bond length is 2.44 Å. There are three shorter (2.68 Å) and six longer (2.75 Å) Sr(2)-O(2) bond lengths. P(1) is bonded to one O(1) and three equivalent O(2) atoms to form PO4 tetrahedra that share corners with three equivalent Sr(1)O6 cuboctahedra. The P(1)-O(1) bond length is 1.53 Å. All P(1)-O(2) bond lengths are 1.55 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted linear geometry to one Sr(2) and one P(1) atom. In the second O site, O(2) is bonded in a distorted single-bond geometry to one Sr(1), three equivalent Sr(2), and one P(1) atom.