SrTi(PO4)2 crystallizes in the monoclinic C2/c space group. Sr(1) is bonded to two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms to form distorted SrO8 hexagonal bipyramids that share corners with four equivalent P(1)O4 tetrahedra, edges with two equivalent Sr(1)O8 hexagonal bipyramids, edges with two equivalent Ti(1)O6 octahedra, and edges with two equivalent P(1)O4 tetrahedra. Ti(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TiO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with two equivalent Sr(1)O8 hexagonal 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 two equivalent Sr(1)O8 hexagonal bipyramids, corners with three equivalent Ti(1)O6 octahedra, and  an edgeedge with one Sr(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 31-49°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Sr(1), one Ti(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sr(1), one Ti(1), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Sr(1) and one P(1) atom.
SrTi(PO4)2 crystallizes in the monoclinic C2/c space group. Sr(1) is bonded to two equivalent O(1), two equivalent O(2), and four equivalent O(4) atoms to form distorted SrO8 hexagonal bipyramids that share corners with four equivalent P(1)O4 tetrahedra, edges with two equivalent Sr(1)O8 hexagonal bipyramids, edges with two equivalent Ti(1)O6 octahedra, and edges with two equivalent P(1)O4 tetrahedra. Both Sr(1)-O(1) bond lengths are 2.73 Å. Both Sr(1)-O(2) bond lengths are 2.66 Å. There are two shorter (2.66 Å) and two longer (2.77 Å) Sr(1)-O(4) bond lengths. Ti(1) is bonded to two equivalent O(1), two equivalent O(2), and two equivalent O(3) atoms to form TiO6 octahedra that share corners with six equivalent P(1)O4 tetrahedra and edges with two equivalent Sr(1)O8 hexagonal bipyramids. Both Ti(1)-O(1) bond lengths are 1.99 Å. Both Ti(1)-O(2) bond lengths are 2.01 Å. Both Ti(1)-O(3) bond lengths are 1.90 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 two equivalent Sr(1)O8 hexagonal bipyramids, corners with three equivalent Ti(1)O6 octahedra, and  an edgeedge with one Sr(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 31-49°. The P(1)-O(1) bond length is 1.57 Å. The P(1)-O(2) bond length is 1.56 Å. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.52 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Sr(1), one Ti(1), and one P(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Sr(1), one Ti(1), and one P(1) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Ti(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a distorted single-bond geometry to two equivalent Sr(1) and one P(1) atom.