Na4ScSnSi2PO12 crystallizes in the monoclinic Cc space group. There are four inequivalent Na sites. In the first Na site, Na(1) 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 second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(11), one O(12), one O(3), one O(4), one O(6), one O(8), and one O(9) atom. 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. In the fourth Na site, Na(4) 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. Sc(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 ScO6 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. Sn(1) 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 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(11), one O(2), one O(5), and one O(8) atom to form SiO4 tetrahedra that share corners with two equivalent Sc(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-38°. 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 Sc(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-39°. 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 Sc(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-37°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 2-coordinate geometry to one Na(1), one Sc(1), and one P(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Na(3), one Sc(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Na(1), one Na(2), one Sc(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Sn(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Sn(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Na(2), one Na(3), one Sn(1), and one P(1) atom. In the seventh O site, O(7) is bonded to one Na(1), one Na(3), one Na(4), one Sc(1), and one Si(2) atom to form distorted ONa3ScSi trigonal bipyramids that share  a cornercorner with one O(12)Na3SiSn trigonal bipyramid, corners with two equivalent O(11)Na3SiSn trigonal bipyramids,  an edgeedge with one O(12)Na3SiSn trigonal bipyramid, and  a faceface with one O(8)Na3ScSi trigonal bipyramid. In the eighth O site, O(8) is bonded to one Na(2), one Na(3), one Na(4), one Sc(1), and one Si(1) atom to form distorted ONa3ScSi trigonal bipyramids that share  a cornercorner with one O(11)Na3SiSn trigonal bipyramid, corners with three equivalent O(12)Na3SiSn trigonal bipyramids,  an edgeedge with one O(11)Na3SiSn trigonal bipyramid, and  a faceface with one O(7)Na3ScSi trigonal bipyramid. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(4), one Sc(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(3), one Na(4), one Sn(1), and one P(1) atom. In the eleventh O site, O(11) is bonded to one Na(1), one Na(2), one Na(4), one Sn(1), and one Si(1) atom to form distorted ONa3SiSn trigonal bipyramids that share  a cornercorner with one O(8)Na3ScSi trigonal bipyramid, corners with two equivalent O(7)Na3ScSi trigonal bipyramids,  an edgeedge with one O(8)Na3ScSi trigonal bipyramid, and  a faceface with one O(12)Na3SiSn trigonal bipyramid. In the twelfth O site, O(12) is bonded to one Na(2), one Na(3), one Na(4), one Sn(1), and one Si(2) atom to form distorted ONa3SiSn trigonal bipyramids that share  a cornercorner with one O(7)Na3ScSi trigonal bipyramid, corners with three equivalent O(8)Na3ScSi trigonal bipyramids,  an edgeedge with one O(7)Na3ScSi trigonal bipyramid, and  a faceface with one O(11)Na3SiSn trigonal bipyramid.
Na4ScSnSi2PO12 crystallizes in the monoclinic Cc space group. There are four inequivalent Na sites. In the first Na site, Na(1) 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(1)-O(1) bond length is 2.73 Å. The Na(1)-O(10) bond length is 2.64 Å. The Na(1)-O(11) bond length is 2.50 Å. The Na(1)-O(3) bond length is 2.97 Å. The Na(1)-O(7) bond length is 2.45 Å. The Na(1)-O(9) bond length is 2.52 Å. There is one shorter (2.67 Å) and one longer (2.89 Å) Na(1)-O(5) bond length. In the second Na site, Na(2) is bonded in a 7-coordinate geometry to one O(11), one O(12), one O(3), one O(4), one O(6), one O(8), and one O(9) atom. The Na(2)-O(11) bond length is 2.59 Å. The Na(2)-O(12) bond length is 2.51 Å. The Na(2)-O(3) bond length is 2.57 Å. The Na(2)-O(4) bond length is 2.87 Å. The Na(2)-O(6) bond length is 2.78 Å. The Na(2)-O(8) bond length is 2.45 Å. The Na(2)-O(9) bond length is 2.56 Å. 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 2.55 Å. The Na(3)-O(12) bond length is 2.57 Å. The Na(3)-O(4) bond length is 2.67 Å. The Na(3)-O(6) bond length is 2.98 Å. The Na(3)-O(7) bond length is 2.49 Å. The Na(3)-O(8) bond length is 2.52 Å. There is one shorter (2.66 Å) and one longer (2.95 Å) Na(3)-O(2) bond length. In the fourth Na site, Na(4) 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(4)-O(10) bond length is 2.64 Å. The Na(4)-O(11) bond length is 2.58 Å. The Na(4)-O(12) bond length is 2.52 Å. The Na(4)-O(7) bond length is 2.46 Å. The Na(4)-O(8) bond length is 2.51 Å. The Na(4)-O(9) bond length is 2.64 Å. Sc(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 ScO6 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 Sc(1)-O(1) bond length is 2.13 Å. The Sc(1)-O(2) bond length is 1.99 Å. The Sc(1)-O(3) bond length is 2.02 Å. The Sc(1)-O(7) bond length is 2.13 Å. The Sc(1)-O(8) bond length is 2.09 Å. The Sc(1)-O(9) bond length is 2.22 Å. Sn(1) 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 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(10) bond length is 2.17 Å. The Sn(1)-O(11) bond length is 2.08 Å. The Sn(1)-O(12) bond length is 2.09 Å. The Sn(1)-O(4) bond length is 2.03 Å. The Sn(1)-O(5) bond length is 2.04 Å. The Sn(1)-O(6) bond length is 2.11 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 Sc(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-38°. The Si(1)-O(11) bond length is 1.66 Å. The Si(1)-O(2) bond length is 1.62 Å. The Si(1)-O(5) bond length is 1.66 Å. The Si(1)-O(8) bond length is 1.63 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 Sc(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-39°. The Si(2)-O(12) bond length is 1.67 Å. The Si(2)-O(3) bond length is 1.62 Å. The Si(2)-O(4) bond length is 1.66 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 Sc(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 30-37°. The P(1)-O(1) bond length is 1.53 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 2-coordinate geometry to one Na(1), one Sc(1), and one P(1) atom. In the second O site, O(2) is bonded in a 2-coordinate geometry to two equivalent Na(3), one Sc(1), and one Si(1) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to one Na(1), one Na(2), one Sc(1), and one Si(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Na(2), one Na(3), one Sn(1), and one Si(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Na(1), one Sn(1), and one Si(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to one Na(2), one Na(3), one Sn(1), and one P(1) atom. In the seventh O site, O(7) is bonded to one Na(1), one Na(3), one Na(4), one Sc(1), and one Si(2) atom to form distorted ONa3ScSi trigonal bipyramids that share  a cornercorner with one O(12)Na3SiSn trigonal bipyramid, corners with two equivalent O(11)Na3SiSn trigonal bipyramids,  an edgeedge with one O(12)Na3SiSn trigonal bipyramid, and  a faceface with one O(8)Na3ScSi trigonal bipyramid. In the eighth O site, O(8) is bonded to one Na(2), one Na(3), one Na(4), one Sc(1), and one Si(1) atom to form distorted ONa3ScSi trigonal bipyramids that share  a cornercorner with one O(11)Na3SiSn trigonal bipyramid, corners with three equivalent O(12)Na3SiSn trigonal bipyramids,  an edgeedge with one O(11)Na3SiSn trigonal bipyramid, and  a faceface with one O(7)Na3ScSi trigonal bipyramid. In the ninth O site, O(9) is bonded in a 5-coordinate geometry to one Na(1), one Na(2), one Na(4), one Sc(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(3), one Na(4), one Sn(1), and one P(1) atom. In the eleventh O site, O(11) is bonded to one Na(1), one Na(2), one Na(4), one Sn(1), and one Si(1) atom to form distorted ONa3SiSn trigonal bipyramids that share  a cornercorner with one O(8)Na3ScSi trigonal bipyramid, corners with two equivalent O(7)Na3ScSi trigonal bipyramids,  an edgeedge with one O(8)Na3ScSi trigonal bipyramid, and  a faceface with one O(12)Na3SiSn trigonal bipyramid. In the twelfth O site, O(12) is bonded to one Na(2), one Na(3), one Na(4), one Sn(1), and one Si(2) atom to form distorted ONa3SiSn trigonal bipyramids that share  a cornercorner with one O(7)Na3ScSi trigonal bipyramid, corners with three equivalent O(8)Na3ScSi trigonal bipyramids,  an edgeedge with one O(7)Na3ScSi trigonal bipyramid, and  a faceface with one O(11)Na3SiSn trigonal bipyramid.