Na2FeSn(PO4)3 crystallizes in the monoclinic C2 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(5), one O(6), one O(7), one O(8), and two equivalent O(9) atoms. In the second Na site, Na(2) 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. Fe(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 FeO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)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  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. There are four inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(1) and two equivalent O(12) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-40°. In the second P site, P(2) is bonded to one O(10), one O(11), one O(2), and one O(3) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-41°. In the third P site, P(3) is bonded to one O(4), one O(5), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-37°. In the fourth P site, P(4) is bonded to two equivalent O(6) and two equivalent O(7) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-36°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Sn(1) and one P(3) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Sn(1), and one P(3) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Sn(1), and one P(4) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Fe(1), and one P(4) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), one Fe(1), and one P(3) atom. In the ninth O site, O(9) is bonded to one Na(2), two equivalent Na(1), one Fe(1), and one P(3) atom to form distorted corner-sharing ONa3FeP trigonal bipyramids. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Na(2), one Sn(1), and one P(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(2), one Sn(1), and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Na(2), one Sn(1), and one P(1) atom.
Na2FeSn(PO4)3 crystallizes in the monoclinic C2 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(5), one O(6), one O(7), one O(8), and two equivalent O(9) atoms. The Na(1)-O(1) bond length is 2.63 Å. The Na(1)-O(3) bond length is 2.52 Å. The Na(1)-O(5) bond length is 2.82 Å. The Na(1)-O(6) bond length is 2.83 Å. The Na(1)-O(7) bond length is 2.41 Å. The Na(1)-O(8) bond length is 2.39 Å. There is one shorter (2.42 Å) and one longer (2.43 Å) Na(1)-O(9) bond length. In the second Na site, Na(2) 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(2)-O(10) bond length is 2.38 Å. The Na(2)-O(11) bond length is 2.49 Å. The Na(2)-O(12) bond length is 2.51 Å. The Na(2)-O(7) bond length is 2.45 Å. The Na(2)-O(8) bond length is 2.43 Å. The Na(2)-O(9) bond length is 2.57 Å. Fe(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 FeO6 octahedra that share  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. The Fe(1)-O(1) bond length is 1.99 Å. The Fe(1)-O(2) bond length is 1.92 Å. The Fe(1)-O(3) bond length is 1.99 Å. The Fe(1)-O(7) bond length is 2.07 Å. The Fe(1)-O(8) bond length is 2.06 Å. The Fe(1)-O(9) bond length is 2.14 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  a cornercorner with one P(1)O4 tetrahedra,  a cornercorner with one P(4)O4 tetrahedra, corners with two equivalent P(2)O4 tetrahedra, and corners with two equivalent P(3)O4 tetrahedra. The Sn(1)-O(10) bond length is 2.07 Å. The Sn(1)-O(11) bond length is 2.07 Å. The Sn(1)-O(12) bond length is 2.08 Å. The Sn(1)-O(4) bond length is 2.05 Å. The Sn(1)-O(5) bond length is 2.05 Å. The Sn(1)-O(6) bond length is 2.07 Å. There are four inequivalent P sites. In the first P site, P(1) is bonded to two equivalent O(1) and two equivalent O(12) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 31-40°. Both P(1)-O(1) bond lengths are 1.54 Å. Both P(1)-O(12) bond lengths are 1.56 Å. In the second P site, P(2) is bonded to one O(10), one O(11), one O(2), and one O(3) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 24-41°. The P(2)-O(10) bond length is 1.56 Å. The P(2)-O(11) bond length is 1.56 Å. The P(2)-O(2) bond length is 1.53 Å. The P(2)-O(3) bond length is 1.54 Å. In the third P site, P(3) is bonded to one O(4), one O(5), one O(8), and one O(9) atom to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-37°. The P(3)-O(4) bond length is 1.54 Å. The P(3)-O(5) bond length is 1.55 Å. The P(3)-O(8) bond length is 1.54 Å. The P(3)-O(9) bond length is 1.55 Å. In the fourth P site, P(4) is bonded to two equivalent O(6) and two equivalent O(7) atoms to form PO4 tetrahedra that share corners with two equivalent Fe(1)O6 octahedra and corners with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 28-36°. Both P(4)-O(6) bond lengths are 1.56 Å. Both P(4)-O(7) bond lengths are 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(1), one Fe(1), and one P(1) atom. In the second O site, O(2) is bonded in a bent 150 degrees geometry to one Fe(1) and one P(2) atom. In the third O site, O(3) is bonded in a 3-coordinate geometry to one Na(1), one Fe(1), and one P(2) atom. In the fourth O site, O(4) is bonded in a bent 150 degrees geometry to one Sn(1) and one P(3) atom. In the fifth O site, O(5) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Sn(1), and one P(3) atom. In the sixth O site, O(6) is bonded in a distorted bent 150 degrees geometry to one Na(1), one Sn(1), and one P(4) atom. In the seventh O site, O(7) is bonded in a distorted rectangular see-saw-like geometry to one Na(1), one Na(2), one Fe(1), and one P(4) atom. In the eighth O site, O(8) is bonded in a rectangular see-saw-like geometry to one Na(1), one Na(2), one Fe(1), and one P(3) atom. In the ninth O site, O(9) is bonded to one Na(2), two equivalent Na(1), one Fe(1), and one P(3) atom to form distorted corner-sharing ONa3FeP trigonal bipyramids. In the tenth O site, O(10) is bonded in a 3-coordinate geometry to one Na(2), one Sn(1), and one P(2) atom. In the eleventh O site, O(11) is bonded in a 3-coordinate geometry to one Na(2), one Sn(1), and one P(2) atom. In the twelfth O site, O(12) is bonded in a 3-coordinate geometry to one Na(2), one Sn(1), and one P(1) atom.