RbTiP2O7 crystallizes in the monoclinic P2_1/c space group. Rb(1) is bonded in a 10-coordinate geometry to one O(1), one O(4), one O(5), one O(6), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form TiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three 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(3), and one O(4) atom to form PO4 tetrahedra that share corners with three equivalent Ti(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-47°. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Ti(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 17-51°. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Rb(1), one Ti(1), and one P(2) atom. In the second O site, O(6) is bonded in a distorted linear geometry to one Rb(1), one Ti(1), and one P(2) atom. In the third O site, O(7) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(1), one Ti(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a linear geometry to one Rb(1), one Ti(1), and one P(1) atom. In the fifth O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Rb(1), one Ti(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Rb(1), one Ti(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one Rb(1), one P(1), and one P(2) atom.
RbTiP2O7 crystallizes in the monoclinic P2_1/c space group. Rb(1) is bonded in a 10-coordinate geometry to one O(1), one O(4), one O(5), one O(6), two equivalent O(2), two equivalent O(3), and two equivalent O(7) atoms. The Rb(1)-O(1) bond length is 3.48 Å. The Rb(1)-O(4) bond length is 3.25 Å. The Rb(1)-O(5) bond length is 2.91 Å. The Rb(1)-O(6) bond length is 3.26 Å. There is one shorter (3.01 Å) and one longer (3.08 Å) Rb(1)-O(2) bond length. There is one shorter (2.94 Å) and one longer (3.04 Å) Rb(1)-O(3) bond length. There is one shorter (3.20 Å) and one longer (3.28 Å) Rb(1)-O(7) bond length. Ti(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form TiO6 octahedra that share corners with three equivalent P(1)O4 tetrahedra and corners with three equivalent P(2)O4 tetrahedra. The Ti(1)-O(1) bond length is 1.97 Å. The Ti(1)-O(2) bond length is 2.12 Å. The Ti(1)-O(3) bond length is 2.09 Å. The Ti(1)-O(5) bond length is 2.09 Å. The Ti(1)-O(6) bond length is 2.00 Å. The Ti(1)-O(7) bond length is 2.12 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(3), and one O(4) atom to form PO4 tetrahedra that share corners with three equivalent Ti(1)O6 octahedra and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 14-47°. The P(1)-O(1) bond length is 1.52 Å. The P(1)-O(2) bond length is 1.53 Å. The P(1)-O(3) bond length is 1.54 Å. The P(1)-O(4) bond length is 1.63 Å. In the second P site, P(2) is bonded to one O(4), one O(5), one O(6), and one O(7) atom to form PO4 tetrahedra that share corners with three equivalent Ti(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 17-51°. The P(2)-O(4) bond length is 1.64 Å. The P(2)-O(5) bond length is 1.53 Å. The P(2)-O(6) bond length is 1.54 Å. The P(2)-O(7) bond length is 1.52 Å. There are seven inequivalent O sites. In the first O site, O(5) is bonded in a 3-coordinate geometry to one Rb(1), one Ti(1), and one P(2) atom. In the second O site, O(6) is bonded in a distorted linear geometry to one Rb(1), one Ti(1), and one P(2) atom. In the third O site, O(7) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(1), one Ti(1), and one P(2) atom. In the fourth O site, O(1) is bonded in a linear geometry to one Rb(1), one Ti(1), and one P(1) atom. In the fifth O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Rb(1), one Ti(1), and one P(1) atom. In the sixth O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Rb(1), one Ti(1), and one P(1) atom. In the seventh O site, O(4) is bonded in a bent 120 degrees geometry to one Rb(1), one P(1), and one P(2) atom.