Na3Ti2Si2PO12 crystallizes in the monoclinic Cc space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal planar geometry to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom. In the second Na site, Na(2) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(7), one O(9), and two equivalent O(5) atoms. In the third Na site, Na(3) is bonded in a 8-coordinate geometry to one O(10), one O(12), one O(4), one O(6), one O(7), one O(8), and two equivalent O(2) atoms. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(2), one O(3), one O(7), one O(8), and one O(9) atom to form TiO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. In the second Ti site, Ti(2) is bonded to one O(10), one O(11), one O(12), one O(4), one O(5), and one O(6) atom to form TiO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(2), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-36°. In the second Si site, Si(2) is bonded to one O(12), one O(3), one O(4), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-35°. P(1) is bonded to one O(1), one O(10), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-34°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(2), one Ti(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(3), one Ti(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Na(2), one Ti(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(3), one Ti(2), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(2), one Ti(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(3), one Ti(2), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal bipyramidal geometry to one Na(1), one Na(2), one Na(3), one Ti(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Ti(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Ti(1), and one P(1) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Ti(2), and one P(1) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Ti(2), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Ti(2), and one Si(2) atom.
Na3Ti2Si2PO12 crystallizes in the monoclinic Cc space group. There are three inequivalent Na sites. In the first Na site, Na(1) is bonded in a distorted hexagonal planar geometry to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom. The Na(1)-O(10) bond length is 2.59 Å. The Na(1)-O(11) bond length is 2.54 Å. The Na(1)-O(12) bond length is 2.53 Å. The Na(1)-O(7) bond length is 2.54 Å. The Na(1)-O(8) bond length is 2.55 Å. The Na(1)-O(9) bond length is 2.60 Å. In the second Na site, Na(2) is bonded in a 8-coordinate geometry to one O(1), one O(10), one O(11), one O(3), one O(7), one O(9), and two equivalent O(5) atoms. The Na(2)-O(1) bond length is 2.68 Å. The Na(2)-O(10) bond length is 2.53 Å. The Na(2)-O(11) bond length is 2.37 Å. The Na(2)-O(3) bond length is 2.85 Å. The Na(2)-O(7) bond length is 2.38 Å. The Na(2)-O(9) bond length is 2.46 Å. There is one shorter (2.69 Å) and one longer (2.87 Å) Na(2)-O(5) bond length. In the third Na site, Na(3) is bonded in a 8-coordinate geometry to one O(10), one O(12), one O(4), one O(6), one O(7), one O(8), and two equivalent O(2) atoms. The Na(3)-O(10) bond length is 2.40 Å. The Na(3)-O(12) bond length is 2.45 Å. The Na(3)-O(4) bond length is 2.66 Å. The Na(3)-O(6) bond length is 2.84 Å. The Na(3)-O(7) bond length is 2.53 Å. The Na(3)-O(8) bond length is 2.37 Å. There is one shorter (2.70 Å) and one longer (2.85 Å) Na(3)-O(2) bond length. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded to one O(1), one O(2), one O(3), one O(7), one O(8), and one O(9) atom to form TiO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. The Ti(1)-O(1) bond length is 2.06 Å. The Ti(1)-O(2) bond length is 1.89 Å. The Ti(1)-O(3) bond length is 1.84 Å. The Ti(1)-O(7) bond length is 2.05 Å. The Ti(1)-O(8) bond length is 1.93 Å. The Ti(1)-O(9) bond length is 2.11 Å. In the second Ti site, Ti(2) is bonded to one O(10), one O(11), one O(12), one O(4), one O(5), and one O(6) atom to form TiO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent Si(2)O4 tetrahedra, and corners with two equivalent P(1)O4 tetrahedra. The Ti(2)-O(10) bond length is 2.15 Å. The Ti(2)-O(11) bond length is 2.00 Å. The Ti(2)-O(12) bond length is 1.97 Å. The Ti(2)-O(4) bond length is 1.89 Å. The Ti(2)-O(5) bond length is 1.94 Å. The Ti(2)-O(6) bond length is 1.93 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(11), one O(2), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 29-36°. The Si(1)-O(11) bond length is 1.62 Å. The Si(1)-O(2) bond length is 1.66 Å. The Si(1)-O(5) bond length is 1.64 Å. The Si(1)-O(8) bond length is 1.64 Å. In the second Si site, Si(2) is bonded to one O(12), one O(3), one O(4), and one O(7) atom to form SiO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-35°. The Si(2)-O(12) bond length is 1.63 Å. The Si(2)-O(3) bond length is 1.65 Å. The Si(2)-O(4) bond length is 1.64 Å. The Si(2)-O(7) bond length is 1.64 Å. P(1) is bonded to one O(1), one O(10), one O(6), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Ti(1)O6 octahedra and corners with two equivalent Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-34°. The P(1)-O(1) bond length is 1.54 Å. The P(1)-O(10) bond length is 1.56 Å. The P(1)-O(6) bond length is 1.56 Å. The P(1)-O(9) bond length is 1.54 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(2), one Ti(1), and one P(1) atom. In the second O site, O(2) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(3), one Ti(1), and one Si(1) atom. In the third O site, O(3) is bonded in a distorted bent 150 degrees geometry to one Na(2), one Ti(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a distorted bent 150 degrees geometry to one Na(3), one Ti(2), and one Si(2) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to two equivalent Na(2), one Ti(2), and one Si(1) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(3), one Ti(2), and one P(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal bipyramidal geometry to one Na(1), one Na(2), one Na(3), one Ti(1), and one Si(2) atom. In the eighth O site, O(8) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Ti(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Ti(1), and one P(1) atom. In the tenth O site, O(10) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Ti(2), and one P(1) atom. In the eleventh O site, O(11) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Ti(2), and one Si(1) atom. In the twelfth O site, O(12) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Ti(2), and one Si(2) atom.