Na3Sn2Si2PO12 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(1), one O(11), one O(12), one O(2), one O(5), and one O(6) 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(12), one O(2), one O(7), one O(8), and one O(9) atom. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(1), one O(12), one O(5), one O(6), one O(8), and two equivalent O(3) atoms. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(1), one O(11), one O(4), one O(5), one O(8), and one O(9) atom to form SnO6 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 Sn site, Sn(2) is bonded to one O(10), one O(12), one O(2), one O(3), one O(6), and one O(7) atom to form SnO6 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(2), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra and corners with two equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-42°. In the second Si site, Si(2) is bonded to one O(1), one O(10), one O(6), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra and corners with two equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-41°. P(1) is bonded to one O(11), one O(12), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra and corners with two equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-39°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Sn(1), and one Si(2) atom to form distorted face-sharing ONa3SiSn trigonal bipyramids. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), one Sn(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Na(3), one Sn(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Sn(1) and one P(1) atom. In the fifth O site, O(5) is bonded to one Na(1), one Na(3), one Sn(1), and one Si(1) atom to form distorted face-sharing ONa2SiSn trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Sn(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Na(2), one Sn(2), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(2), one Na(3), one Sn(1), and one Si(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(2), one Sn(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Na(2), one Sn(2), and one Si(2) 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 Sn(1), and one P(1) atom. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Sn(2), and one P(1) atom.
Na3Sn2Si2PO12 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(1), one O(11), one O(12), one O(2), one O(5), and one O(6) atom. The Na(1)-O(1) bond length is 2.58 Å. The Na(1)-O(11) bond length is 2.38 Å. The Na(1)-O(12) bond length is 2.67 Å. The Na(1)-O(2) bond length is 2.38 Å. The Na(1)-O(5) bond length is 2.46 Å. The Na(1)-O(6) bond length is 2.51 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(12), one O(2), one O(7), one O(8), and one O(9) atom. The Na(2)-O(1) bond length is 2.40 Å. The Na(2)-O(10) bond length is 2.55 Å. The Na(2)-O(11) bond length is 2.56 Å. The Na(2)-O(12) bond length is 2.63 Å. The Na(2)-O(2) bond length is 2.39 Å. The Na(2)-O(7) bond length is 2.93 Å. The Na(2)-O(8) bond length is 2.91 Å. The Na(2)-O(9) bond length is 2.53 Å. In the third Na site, Na(3) is bonded in a 7-coordinate geometry to one O(1), one O(12), one O(5), one O(6), one O(8), and two equivalent O(3) atoms. The Na(3)-O(1) bond length is 2.61 Å. The Na(3)-O(12) bond length is 2.44 Å. The Na(3)-O(5) bond length is 2.51 Å. The Na(3)-O(6) bond length is 2.36 Å. The Na(3)-O(8) bond length is 2.46 Å. Both Na(3)-O(3) bond lengths are 2.88 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(1), one O(11), one O(4), one O(5), one O(8), and one O(9) atom to form SnO6 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 Sn(1)-O(1) bond length is 2.09 Å. The Sn(1)-O(11) bond length is 2.16 Å. The Sn(1)-O(4) bond length is 2.06 Å. The Sn(1)-O(5) bond length is 2.05 Å. The Sn(1)-O(8) bond length is 2.03 Å. The Sn(1)-O(9) bond length is 2.03 Å. In the second Sn site, Sn(2) is bonded to one O(10), one O(12), one O(2), one O(3), one O(6), and one O(7) atom to form SnO6 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 Sn(2)-O(10) bond length is 2.04 Å. The Sn(2)-O(12) bond length is 2.18 Å. The Sn(2)-O(2) bond length is 2.06 Å. The Sn(2)-O(3) bond length is 2.12 Å. The Sn(2)-O(6) bond length is 2.06 Å. The Sn(2)-O(7) bond length is 1.99 Å. There are two inequivalent Si sites. In the first Si site, Si(1) is bonded to one O(2), one O(5), one O(7), and one O(9) atom to form SiO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra and corners with two equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 18-42°. The Si(1)-O(2) bond length is 1.64 Å. The Si(1)-O(5) bond length is 1.64 Å. The Si(1)-O(7) bond length is 1.63 Å. The Si(1)-O(9) bond length is 1.65 Å. In the second Si site, Si(2) is bonded to one O(1), one O(10), one O(6), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra and corners with two equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 27-41°. The Si(2)-O(1) bond length is 1.66 Å. The Si(2)-O(10) bond length is 1.64 Å. The Si(2)-O(6) bond length is 1.64 Å. The Si(2)-O(8) bond length is 1.64 Å. P(1) is bonded to one O(11), one O(12), one O(3), and one O(4) atom to form PO4 tetrahedra that share corners with two equivalent Sn(1)O6 octahedra and corners with two equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-39°. The P(1)-O(11) bond length is 1.54 Å. The P(1)-O(12) bond length is 1.56 Å. The P(1)-O(3) bond length is 1.55 Å. The P(1)-O(4) bond length is 1.53 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded to one Na(1), one Na(2), one Na(3), one Sn(1), and one Si(2) atom to form distorted face-sharing ONa3SiSn trigonal bipyramids. In the second O site, O(2) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), one Sn(2), and one Si(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Na(3), one Sn(2), and one P(1) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Sn(1) and one P(1) atom. In the fifth O site, O(5) is bonded to one Na(1), one Na(3), one Sn(1), and one Si(1) atom to form distorted face-sharing ONa2SiSn trigonal pyramids. In the sixth O site, O(6) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(3), one Sn(2), and one Si(2) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to one Na(2), one Sn(2), and one Si(1) atom. In the eighth O site, O(8) is bonded in a 3-coordinate geometry to one Na(2), one Na(3), one Sn(1), and one Si(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Na(2), one Sn(1), and one Si(1) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Na(2), one Sn(2), and one Si(2) 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 Sn(1), and one P(1) atom. In the twelfth O site, O(12) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Sn(2), and one P(1) atom.