SrCaTi(PO4)2 crystallizes in the triclinic P-1 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(8), two equivalent O(1), and two equivalent O(6) atoms. Ca(1) is bonded to one O(1), one O(2), one O(4), one O(7), and two equivalent O(5) atoms to form CaO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. Ti(1) is bonded in a 6-coordinate geometry to one O(3), one O(4), one O(5), one O(7), and two equivalent O(8) atoms. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra and  an edgeedge with one Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles are 61°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-57°. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Ca(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 Ca(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Ti(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), one Ca(1), one Ti(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Ti(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Sr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Ca(1), one Ti(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Sr(1), two equivalent Ti(1), and one P(2) atom.
SrCaTi(PO4)2 crystallizes in the triclinic P-1 space group. Sr(1) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(8), two equivalent O(1), and two equivalent O(6) atoms. The Sr(1)-O(2) bond length is 2.60 Å. The Sr(1)-O(3) bond length is 2.59 Å. The Sr(1)-O(4) bond length is 2.86 Å. The Sr(1)-O(8) bond length is 2.90 Å. There is one shorter (2.60 Å) and one longer (2.80 Å) Sr(1)-O(1) bond length. There is one shorter (2.55 Å) and one longer (2.72 Å) Sr(1)-O(6) bond length. Ca(1) is bonded to one O(1), one O(2), one O(4), one O(7), and two equivalent O(5) atoms to form CaO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra, corners with three equivalent P(2)O4 tetrahedra,  an edgeedge with one Ca(1)O6 octahedra, and  an edgeedge with one P(1)O4 tetrahedra. The Ca(1)-O(1) bond length is 2.43 Å. The Ca(1)-O(2) bond length is 2.30 Å. The Ca(1)-O(4) bond length is 2.32 Å. The Ca(1)-O(7) bond length is 2.39 Å. There is one shorter (2.32 Å) and one longer (2.46 Å) Ca(1)-O(5) bond length. Ti(1) is bonded in a 6-coordinate geometry to one O(3), one O(4), one O(5), one O(7), and two equivalent O(8) atoms. The Ti(1)-O(3) bond length is 2.19 Å. The Ti(1)-O(4) bond length is 2.16 Å. The Ti(1)-O(5) bond length is 2.56 Å. The Ti(1)-O(7) bond length is 2.06 Å. There is one shorter (2.18 Å) and one longer (2.21 Å) Ti(1)-O(8) bond length. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(3), and one O(7) atom to form PO4 tetrahedra that share  a cornercorner with one Ca(1)O6 octahedra and  an edgeedge with one Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles are 61°. The P(1)-O(1) bond length is 1.56 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(7) bond length is 1.57 Å. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(8) atom to form PO4 tetrahedra that share corners with three equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 52-57°. The P(2)-O(4) bond length is 1.58 Å. The P(2)-O(5) bond length is 1.57 Å. The P(2)-O(6) bond length is 1.52 Å. The P(2)-O(8) bond length is 1.58 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to two equivalent Sr(1), one Ca(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 Ca(1), and one P(1) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Sr(1), one Ti(1), and one P(1) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Sr(1), one Ca(1), one Ti(1), and one P(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(1), one Ti(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted single-bond geometry to two equivalent Sr(1) and one P(2) atom. In the seventh O site, O(7) is bonded in a distorted T-shaped geometry to one Ca(1), one Ti(1), and one P(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Sr(1), two equivalent Ti(1), and one P(2) atom.