Na3YSnSi(PO6)2 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 6-coordinate geometry to one O(11), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. Y(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 YO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. Sn(1) 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 P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. Si(1) 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 Y(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-41°. There are two inequivalent P sites. In the first P site, 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 Y(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-43°. In the second P site, P(2) is bonded to one O(2), one O(5), one O(7), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Y(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-41°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), one Y(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Na(1), one Na(2), one Sn(1), and one P(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Sn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Na(3), one Y(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Na(3), one Y(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal pyramidal geometry to one Na(1), one Na(3), one Sn(1), and one Si(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Sn(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Na(2), one Na(3), one Y(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to one Na(2), one Y(1), and one P(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Na(2), one Sn(1), and one Si(1) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Y(1), and one P(1) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Sn(1), and one P(1) atom.
Na3YSnSi(PO6)2 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 2.45 Å. The Na(1)-O(11) bond length is 2.75 Å. The Na(1)-O(12) bond length is 2.38 Å. The Na(1)-O(2) bond length is 2.62 Å. The Na(1)-O(5) bond length is 2.74 Å. The Na(1)-O(6) bond length is 2.46 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 2.41 Å. The Na(2)-O(10) bond length is 2.62 Å. The Na(2)-O(11) bond length is 2.78 Å. The Na(2)-O(12) bond length is 2.85 Å. The Na(2)-O(2) bond length is 2.42 Å. The Na(2)-O(7) bond length is 2.87 Å. The Na(2)-O(8) bond length is 2.94 Å. The Na(2)-O(9) bond length is 2.86 Å. In the third Na site, Na(3) is bonded in a 6-coordinate geometry to one O(11), one O(4), one O(5), one O(6), one O(7), and one O(8) atom. The Na(3)-O(11) bond length is 2.53 Å. The Na(3)-O(4) bond length is 2.80 Å. The Na(3)-O(5) bond length is 2.60 Å. The Na(3)-O(6) bond length is 2.49 Å. The Na(3)-O(7) bond length is 2.49 Å. The Na(3)-O(8) bond length is 2.76 Å. Y(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 YO6 octahedra that share corners with two equivalent Si(1)O4 tetrahedra, corners with two equivalent P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. The Y(1)-O(1) bond length is 2.21 Å. The Y(1)-O(11) bond length is 2.30 Å. The Y(1)-O(4) bond length is 2.23 Å. The Y(1)-O(5) bond length is 2.26 Å. The Y(1)-O(8) bond length is 2.09 Å. The Y(1)-O(9) bond length is 2.21 Å. Sn(1) 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 P(1)O4 tetrahedra, and corners with two equivalent P(2)O4 tetrahedra. The Sn(1)-O(10) bond length is 2.05 Å. The Sn(1)-O(12) bond length is 2.14 Å. The Sn(1)-O(2) bond length is 2.21 Å. The Sn(1)-O(3) bond length is 2.08 Å. The Sn(1)-O(6) bond length is 2.05 Å. The Sn(1)-O(7) bond length is 2.23 Å. Si(1) 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 Y(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 14-41°. The Si(1)-O(1) bond length is 1.62 Å. The Si(1)-O(10) bond length is 1.69 Å. The Si(1)-O(6) bond length is 1.67 Å. The Si(1)-O(8) bond length is 1.60 Å. There are two inequivalent P sites. In the first P site, 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 Y(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-43°. The P(1)-O(11) bond length is 1.55 Å. The P(1)-O(12) bond length is 1.57 Å. The P(1)-O(3) bond length is 1.57 Å. The P(1)-O(4) bond length is 1.52 Å. In the second P site, P(2) is bonded to one O(2), one O(5), one O(7), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Y(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 26-41°. The P(2)-O(2) bond length is 1.58 Å. The P(2)-O(5) bond length is 1.54 Å. The P(2)-O(7) bond length is 1.59 Å. The P(2)-O(9) bond length is 1.52 Å. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), one Y(1), and one Si(1) atom. In the second O site, O(2) is bonded in a 1-coordinate geometry to one Na(1), one Na(2), one Sn(1), and one P(2) atom. In the third O site, O(3) is bonded in a bent 150 degrees geometry to one Sn(1) and one P(1) atom. In the fourth O site, O(4) is bonded in a 2-coordinate geometry to one Na(3), one Y(1), and one P(1) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to one Na(1), one Na(3), one Y(1), and one P(2) atom. In the sixth O site, O(6) is bonded in a distorted trigonal pyramidal geometry to one Na(1), one Na(3), one Sn(1), and one Si(1) atom. In the seventh O site, O(7) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Sn(1), and one P(2) atom. In the eighth O site, O(8) is bonded in a 2-coordinate geometry to one Na(2), one Na(3), one Y(1), and one Si(1) atom. In the ninth O site, O(9) is bonded in a 2-coordinate geometry to one Na(2), one Y(1), and one P(2) atom. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Na(2), one Sn(1), and one Si(1) atom. In the eleventh O site, O(11) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(3), one Y(1), and one P(1) atom. In the twelfth O site, O(12) is bonded in a 4-coordinate geometry to one Na(1), one Na(2), one Sn(1), and one P(1) atom.