Rb2SiP4O13 crystallizes in the triclinic P-1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to one O(5), one O(6), one O(7), three equivalent O(1), and three equivalent O(8) atoms. In the second Rb site, Rb(2) is bonded in a 11-coordinate geometry to one O(13), one O(3), one O(4), two equivalent O(2), three equivalent O(10), and three equivalent O(9) atoms. Si(1) is bonded to one O(13), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form SiO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(4)O4 tetrahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(12), one O(3), one O(6), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Si(1)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. In the second P site, P(2) is bonded to one O(1), one O(11), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Si(1)O6 octahedra and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-45°. In the third P site, P(3) is bonded to one O(11), one O(3), one O(4), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Si(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. In the fourth P site, P(4) is bonded to one O(10), one O(12), one O(13), and one O(2) atom to form PO4 tetrahedra that share corners with two equivalent Si(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-44°. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(2), one Si(1), and one P(4) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Rb(2), one P(1), and one P(3) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Rb(2), one Si(1), and one P(3) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Si(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Rb(1), one Si(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Si(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one P(1) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to three equivalent Rb(2) and one P(3) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to three equivalent Rb(2) and one P(4) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one P(1) and one P(4) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 150 degrees geometry to one Rb(2), one Si(1), and one P(4) atom.
Rb2SiP4O13 crystallizes in the triclinic P-1 space group. There are two inequivalent Rb sites. In the first Rb site, Rb(1) is bonded in a 9-coordinate geometry to one O(5), one O(6), one O(7), three equivalent O(1), and three equivalent O(8) atoms. The Rb(1)-O(5) bond length is 3.30 Å. The Rb(1)-O(6) bond length is 2.98 Å. The Rb(1)-O(7) bond length is 3.45 Å. There are a spread of Rb(1)-O(1) bond distances ranging from 2.79-3.21 Å. There are a spread of Rb(1)-O(8) bond distances ranging from 2.93-3.20 Å. In the second Rb site, Rb(2) is bonded in a 11-coordinate geometry to one O(13), one O(3), one O(4), two equivalent O(2), three equivalent O(10), and three equivalent O(9) atoms. The Rb(2)-O(13) bond length is 3.05 Å. The Rb(2)-O(3) bond length is 3.45 Å. The Rb(2)-O(4) bond length is 3.15 Å. There is one shorter (3.50 Å) and one longer (3.51 Å) Rb(2)-O(2) bond length. There are a spread of Rb(2)-O(10) bond distances ranging from 2.88-3.45 Å. There are a spread of Rb(2)-O(9) bond distances ranging from 2.89-3.34 Å. Si(1) is bonded to one O(13), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form SiO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(3)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(4)O4 tetrahedra. The Si(1)-O(13) bond length is 1.77 Å. The Si(1)-O(2) bond length is 1.79 Å. The Si(1)-O(4) bond length is 1.77 Å. The Si(1)-O(5) bond length is 1.77 Å. The Si(1)-O(6) bond length is 1.77 Å. The Si(1)-O(7) bond length is 1.76 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to one O(12), one O(3), one O(6), and one O(8) atom to form PO4 tetrahedra that share  a cornercorner with one Si(1)O6 octahedra,  a cornercorner with one P(3)O4 tetrahedra, and  a cornercorner with one P(4)O4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. The P(1)-O(12) bond length is 1.58 Å. The P(1)-O(3) bond length is 1.59 Å. The P(1)-O(6) bond length is 1.52 Å. The P(1)-O(8) bond length is 1.46 Å. In the second P site, P(2) is bonded to one O(1), one O(11), one O(5), and one O(7) atom to form PO4 tetrahedra that share corners with two equivalent Si(1)O6 octahedra and  a cornercorner with one P(3)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 41-45°. The P(2)-O(1) bond length is 1.47 Å. The P(2)-O(11) bond length is 1.62 Å. The P(2)-O(5) bond length is 1.53 Å. The P(2)-O(7) bond length is 1.54 Å. In the third P site, P(3) is bonded to one O(11), one O(3), one O(4), and one O(9) atom to form PO4 tetrahedra that share  a cornercorner with one Si(1)O6 octahedra,  a cornercorner with one P(1)O4 tetrahedra, and  a cornercorner with one P(2)O4 tetrahedra. The corner-sharing octahedral tilt angles are 44°. The P(3)-O(11) bond length is 1.57 Å. The P(3)-O(3) bond length is 1.59 Å. The P(3)-O(4) bond length is 1.52 Å. The P(3)-O(9) bond length is 1.47 Å. In the fourth P site, P(4) is bonded to one O(10), one O(12), one O(13), and one O(2) atom to form PO4 tetrahedra that share corners with two equivalent Si(1)O6 octahedra and  a cornercorner with one P(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 40-44°. The P(4)-O(10) bond length is 1.47 Å. The P(4)-O(12) bond length is 1.63 Å. The P(4)-O(13) bond length is 1.54 Å. The P(4)-O(2) bond length is 1.53 Å. There are thirteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one P(2) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Rb(2), one Si(1), and one P(4) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Rb(2), one P(1), and one P(3) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Rb(2), one Si(1), and one P(3) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Si(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Rb(1), one Si(1), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted bent 150 degrees geometry to one Rb(1), one Si(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a distorted single-bond geometry to three equivalent Rb(1) and one P(1) atom. In the ninth O site, O(9) is bonded in a distorted single-bond geometry to three equivalent Rb(2) and one P(3) atom. In the tenth O site, O(10) is bonded in a distorted single-bond geometry to three equivalent Rb(2) and one P(4) atom. In the eleventh O site, O(11) is bonded in a bent 120 degrees geometry to one P(2) and one P(3) atom. In the twelfth O site, O(12) is bonded in a bent 120 degrees geometry to one P(1) and one P(4) atom. In the thirteenth O site, O(13) is bonded in a distorted bent 150 degrees geometry to one Rb(2), one Si(1), and one P(4) atom.