Cs2Ti(PO4)2 crystallizes in the orthorhombic P2_12_12_1 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), one O(7), one O(8), and two equivalent O(3) atoms. In the second Cs site, Cs(2) is bonded in a 9-coordinate geometry to one O(1), one O(3), one O(5), one O(6), one O(8), two equivalent O(4), and two equivalent O(7) atoms. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(8) atom to form distorted TiO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with two equivalent Ti(1)O5 trigonal bipyramids. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Ti(1)O5 trigonal bipyramids. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one Cs(1), two equivalent Cs(2), and one P(1) atom. In the second O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Cs(1), one Cs(2), one P(1), and one P(2) atom. In the third O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Cs(2), one Ti(1), and one P(2) atom. In the fourth O site, O(7) is bonded in a distorted single-bond geometry to one Cs(1), two equivalent Cs(2), and one P(2) atom. In the fifth O site, O(8) is bonded in a 2-coordinate geometry to one Cs(1), one Cs(2), one Ti(1), and one P(2) atom. In the sixth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Cs(2), one Ti(1), and one P(1) atom. In the seventh O site, O(2) is bonded in a 2-coordinate geometry to one Cs(1), one Ti(1), and one P(1) atom. In the eighth O site, O(3) is bonded in a distorted single-bond geometry to one Cs(2), two equivalent Cs(1), and one Ti(1) atom.
Cs2Ti(PO4)2 crystallizes in the orthorhombic P2_12_12_1 space group. There are two inequivalent Cs sites. In the first Cs site, Cs(1) is bonded in a 9-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(6), one O(7), one O(8), and two equivalent O(3) atoms. The Cs(1)-O(1) bond length is 3.64 Å. The Cs(1)-O(2) bond length is 3.45 Å. The Cs(1)-O(4) bond length is 3.05 Å. The Cs(1)-O(5) bond length is 3.27 Å. The Cs(1)-O(6) bond length is 3.67 Å. The Cs(1)-O(7) bond length is 3.38 Å. The Cs(1)-O(8) bond length is 3.53 Å. There is one shorter (3.05 Å) and one longer (3.17 Å) Cs(1)-O(3) bond length. In the second Cs site, Cs(2) is bonded in a 9-coordinate geometry to one O(1), one O(3), one O(5), one O(6), one O(8), two equivalent O(4), and two equivalent O(7) atoms. The Cs(2)-O(1) bond length is 3.38 Å. The Cs(2)-O(3) bond length is 3.43 Å. The Cs(2)-O(5) bond length is 3.64 Å. The Cs(2)-O(6) bond length is 3.64 Å. The Cs(2)-O(8) bond length is 3.45 Å. There is one shorter (3.09 Å) and one longer (3.25 Å) Cs(2)-O(4) bond length. There is one shorter (3.04 Å) and one longer (3.15 Å) Cs(2)-O(7) bond length. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(6), and one O(8) atom to form distorted TiO5 trigonal bipyramids that share corners with two equivalent P(1)O4 tetrahedra and corners with two equivalent P(2)O4 tetrahedra. The Ti(1)-O(1) bond length is 2.00 Å. The Ti(1)-O(2) bond length is 2.00 Å. The Ti(1)-O(3) bond length is 1.67 Å. The Ti(1)-O(6) bond length is 1.98 Å. The Ti(1)-O(8) bond length is 2.02 Å. There are two inequivalent P sites. In the first P site, P(1) is bonded to one O(1), one O(2), one O(4), and one O(5) atom to form PO4 tetrahedra that share  a cornercorner with one P(2)O4 tetrahedra and corners with two equivalent Ti(1)O5 trigonal bipyramids. The P(1)-O(1) bond length is 1.55 Å. The P(1)-O(2) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.50 Å. The P(1)-O(5) bond length is 1.64 Å. In the second P site, P(2) is bonded to one O(5), one O(6), one O(7), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one P(1)O4 tetrahedra and corners with two equivalent Ti(1)O5 trigonal bipyramids. The P(2)-O(5) bond length is 1.65 Å. The P(2)-O(6) bond length is 1.54 Å. The P(2)-O(7) bond length is 1.50 Å. The P(2)-O(8) bond length is 1.55 Å. There are eight inequivalent O sites. In the first O site, O(4) is bonded in a distorted single-bond geometry to one Cs(1), two equivalent Cs(2), and one P(1) atom. In the second O site, O(5) is bonded in a distorted bent 120 degrees geometry to one Cs(1), one Cs(2), one P(1), and one P(2) atom. In the third O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Cs(2), one Ti(1), and one P(2) atom. In the fourth O site, O(7) is bonded in a distorted single-bond geometry to one Cs(1), two equivalent Cs(2), and one P(2) atom. In the fifth O site, O(8) is bonded in a 2-coordinate geometry to one Cs(1), one Cs(2), one Ti(1), and one P(2) atom. In the sixth O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Cs(1), one Cs(2), one Ti(1), and one P(1) atom. In the seventh O site, O(2) is bonded in a 2-coordinate geometry to one Cs(1), one Ti(1), and one P(1) atom. In the eighth O site, O(3) is bonded in a distorted single-bond geometry to one Cs(2), two equivalent Cs(1), and one Ti(1) atom.