NaFeSnO4 crystallizes in the orthorhombic Pmc2_1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), two equivalent O(5), and two equivalent O(8) atoms. In the second Na site, Na(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(7), two equivalent O(6), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with four equivalent Sn(2)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-56°. In the second Fe site, Fe(2) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with four equivalent Sn(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(4), one O(8), two equivalent O(5), and two equivalent O(7) atoms to form SnO6 octahedra that share corners with four equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. In the second Sn site, Sn(2) is bonded to one O(2), one O(6), two equivalent O(1), and two equivalent O(3) atoms to form SnO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-56°. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(2), one Fe(2), and two equivalent Sn(2) atoms to form distorted ONa2FeSn2 trigonal bipyramids that share corners with two equivalent O(7)Na2FeSn2 square pyramids,  a cornercorner with one O(5)Na2FeSn2 trigonal bipyramid, corners with two equivalent O(6)Na2Fe2Sn trigonal bipyramids,  an edgeedge with one O(7)Na2FeSn2 square pyramid, edges with two equivalent O(2)Na2Fe2Sn trigonal bipyramids, edges with two equivalent O(6)Na2Fe2Sn trigonal bipyramids, and edges with two equivalent O(1)Na2FeSn2 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Fe(2), and one Sn(2) atom to form distorted ONa2Fe2Sn trigonal bipyramids that share corners with two equivalent O(8)Na2Fe2Sn square pyramids,  a cornercorner with one O(6)Na2Fe2Sn trigonal bipyramid, corners with two equivalent O(5)Na2FeSn2 trigonal bipyramids,  an edgeedge with one O(8)Na2Fe2Sn square pyramid, edges with two equivalent O(2)Na2Fe2Sn trigonal bipyramids, edges with two equivalent O(1)Na2FeSn2 trigonal bipyramids, and edges with two equivalent O(5)Na2FeSn2 trigonal bipyramids. In the third O site, O(3) is bonded in a 5-coordinate geometry to two equivalent Na(2), one Fe(1), and two equivalent Sn(2) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent Na(1), two equivalent Fe(2), and one Sn(1) atom. In the fifth O site, O(5) is bonded to two equivalent Na(1), one Fe(2), and two equivalent Sn(1) atoms to form distorted ONa2FeSn2 trigonal bipyramids that share corners with two equivalent O(8)Na2Fe2Sn square pyramids, corners with two equivalent O(7)Na2FeSn2 square pyramids,  a cornercorner with one O(1)Na2FeSn2 trigonal bipyramid, corners with two equivalent O(2)Na2Fe2Sn trigonal bipyramids, corners with four equivalent O(5)Na2FeSn2 trigonal bipyramids,  an edgeedge with one O(7)Na2FeSn2 square pyramid, edges with two equivalent O(8)Na2Fe2Sn square pyramids, and edges with two equivalent O(2)Na2Fe2Sn trigonal bipyramids. In the sixth O site, O(6) is bonded to two equivalent Na(2), two equivalent Fe(1), and one Sn(2) atom to form distorted ONa2Fe2Sn trigonal bipyramids that share corners with two equivalent O(8)Na2Fe2Sn square pyramids, corners with two equivalent O(7)Na2FeSn2 square pyramids,  a cornercorner with one O(2)Na2Fe2Sn trigonal bipyramid, corners with two equivalent O(1)Na2FeSn2 trigonal bipyramids, corners with four equivalent O(6)Na2Fe2Sn trigonal bipyramids,  an edgeedge with one O(8)Na2Fe2Sn square pyramid, edges with two equivalent O(7)Na2FeSn2 square pyramids, and edges with two equivalent O(1)Na2FeSn2 trigonal bipyramids. In the seventh O site, O(7) is bonded to two equivalent Na(2), one Fe(1), and two equivalent Sn(1) atoms to form ONa2FeSn2 square pyramids that share corners with two equivalent O(6)Na2Fe2Sn trigonal bipyramids, corners with two equivalent O(1)Na2FeSn2 trigonal bipyramids, corners with two equivalent O(5)Na2FeSn2 trigonal bipyramids, edges with two equivalent O(8)Na2Fe2Sn square pyramids, edges with two equivalent O(7)Na2FeSn2 square pyramids,  an edgeedge with one O(1)Na2FeSn2 trigonal bipyramid,  an edgeedge with one O(5)Na2FeSn2 trigonal bipyramid, and edges with two equivalent O(6)Na2Fe2Sn trigonal bipyramids. In the eighth O site, O(8) is bonded to two equivalent Na(1), two equivalent Fe(1), and one Sn(1) atom to form ONa2Fe2Sn square pyramids that share corners with two equivalent O(2)Na2Fe2Sn trigonal bipyramids, corners with two equivalent O(6)Na2Fe2Sn trigonal bipyramids, corners with two equivalent O(5)Na2FeSn2 trigonal bipyramids, edges with two equivalent O(8)Na2Fe2Sn square pyramids, edges with two equivalent O(7)Na2FeSn2 square pyramids,  an edgeedge with one O(2)Na2Fe2Sn trigonal bipyramid,  an edgeedge with one O(6)Na2Fe2Sn trigonal bipyramid, and edges with two equivalent O(5)Na2FeSn2 trigonal bipyramids.
NaFeSnO4 crystallizes in the orthorhombic Pmc2_1 space group. There are two inequivalent Na sites. In the first Na site, Na(1) is bonded in a 8-coordinate geometry to two equivalent O(2), two equivalent O(4), two equivalent O(5), and two equivalent O(8) atoms. Both Na(1)-O(2) bond lengths are 2.48 Å. Both Na(1)-O(4) bond lengths are 2.70 Å. There is one shorter (2.62 Å) and one longer (2.66 Å) Na(1)-O(5) bond length. Both Na(1)-O(8) bond lengths are 2.49 Å. In the second Na site, Na(2) is bonded in a 8-coordinate geometry to two equivalent O(1), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. Both Na(2)-O(1) bond lengths are 2.47 Å. Both Na(2)-O(3) bond lengths are 2.66 Å. There is one shorter (2.57 Å) and one longer (2.69 Å) Na(2)-O(6) bond length. Both Na(2)-O(7) bond lengths are 2.44 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(7), two equivalent O(6), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with four equivalent Sn(2)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-56°. The Fe(1)-O(3) bond length is 2.08 Å. The Fe(1)-O(7) bond length is 2.11 Å. Both Fe(1)-O(6) bond lengths are 2.05 Å. Both Fe(1)-O(8) bond lengths are 2.08 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(5), two equivalent O(2), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with four equivalent Sn(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. The Fe(2)-O(1) bond length is 2.09 Å. The Fe(2)-O(5) bond length is 2.06 Å. Both Fe(2)-O(2) bond lengths are 2.09 Å. Both Fe(2)-O(4) bond lengths are 2.08 Å. There are two inequivalent Sn sites. In the first Sn site, Sn(1) is bonded to one O(4), one O(8), two equivalent O(5), and two equivalent O(7) atoms to form SnO6 octahedra that share corners with four equivalent Fe(2)O6 octahedra, edges with two equivalent Fe(1)O6 octahedra, and edges with two equivalent Sn(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 48-57°. The Sn(1)-O(4) bond length is 2.10 Å. The Sn(1)-O(8) bond length is 2.12 Å. Both Sn(1)-O(5) bond lengths are 2.09 Å. Both Sn(1)-O(7) bond lengths are 2.11 Å. In the second Sn site, Sn(2) is bonded to one O(2), one O(6), two equivalent O(1), and two equivalent O(3) atoms to form SnO6 octahedra that share corners with four equivalent Fe(1)O6 octahedra, edges with two equivalent Fe(2)O6 octahedra, and edges with two equivalent Sn(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 50-56°. The Sn(2)-O(2) bond length is 2.09 Å. The Sn(2)-O(6) bond length is 2.09 Å. Both Sn(2)-O(1) bond lengths are 2.12 Å. Both Sn(2)-O(3) bond lengths are 2.12 Å. There are eight inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Na(2), one Fe(2), and two equivalent Sn(2) atoms to form distorted ONa2FeSn2 trigonal bipyramids that share corners with two equivalent O(7)Na2FeSn2 square pyramids,  a cornercorner with one O(5)Na2FeSn2 trigonal bipyramid, corners with two equivalent O(6)Na2Fe2Sn trigonal bipyramids,  an edgeedge with one O(7)Na2FeSn2 square pyramid, edges with two equivalent O(2)Na2Fe2Sn trigonal bipyramids, edges with two equivalent O(6)Na2Fe2Sn trigonal bipyramids, and edges with two equivalent O(1)Na2FeSn2 trigonal bipyramids. In the second O site, O(2) is bonded to two equivalent Na(1), two equivalent Fe(2), and one Sn(2) atom to form distorted ONa2Fe2Sn trigonal bipyramids that share corners with two equivalent O(8)Na2Fe2Sn square pyramids,  a cornercorner with one O(6)Na2Fe2Sn trigonal bipyramid, corners with two equivalent O(5)Na2FeSn2 trigonal bipyramids,  an edgeedge with one O(8)Na2Fe2Sn square pyramid, edges with two equivalent O(2)Na2Fe2Sn trigonal bipyramids, edges with two equivalent O(1)Na2FeSn2 trigonal bipyramids, and edges with two equivalent O(5)Na2FeSn2 trigonal bipyramids. In the third O site, O(3) is bonded in a 5-coordinate geometry to two equivalent Na(2), one Fe(1), and two equivalent Sn(2) atoms. In the fourth O site, O(4) is bonded in a 5-coordinate geometry to two equivalent Na(1), two equivalent Fe(2), and one Sn(1) atom. In the fifth O site, O(5) is bonded to two equivalent Na(1), one Fe(2), and two equivalent Sn(1) atoms to form distorted ONa2FeSn2 trigonal bipyramids that share corners with two equivalent O(8)Na2Fe2Sn square pyramids, corners with two equivalent O(7)Na2FeSn2 square pyramids,  a cornercorner with one O(1)Na2FeSn2 trigonal bipyramid, corners with two equivalent O(2)Na2Fe2Sn trigonal bipyramids, corners with four equivalent O(5)Na2FeSn2 trigonal bipyramids,  an edgeedge with one O(7)Na2FeSn2 square pyramid, edges with two equivalent O(8)Na2Fe2Sn square pyramids, and edges with two equivalent O(2)Na2Fe2Sn trigonal bipyramids. In the sixth O site, O(6) is bonded to two equivalent Na(2), two equivalent Fe(1), and one Sn(2) atom to form distorted ONa2Fe2Sn trigonal bipyramids that share corners with two equivalent O(8)Na2Fe2Sn square pyramids, corners with two equivalent O(7)Na2FeSn2 square pyramids,  a cornercorner with one O(2)Na2Fe2Sn trigonal bipyramid, corners with two equivalent O(1)Na2FeSn2 trigonal bipyramids, corners with four equivalent O(6)Na2Fe2Sn trigonal bipyramids,  an edgeedge with one O(8)Na2Fe2Sn square pyramid, edges with two equivalent O(7)Na2FeSn2 square pyramids, and edges with two equivalent O(1)Na2FeSn2 trigonal bipyramids. In the seventh O site, O(7) is bonded to two equivalent Na(2), one Fe(1), and two equivalent Sn(1) atoms to form ONa2FeSn2 square pyramids that share corners with two equivalent O(6)Na2Fe2Sn trigonal bipyramids, corners with two equivalent O(1)Na2FeSn2 trigonal bipyramids, corners with two equivalent O(5)Na2FeSn2 trigonal bipyramids, edges with two equivalent O(8)Na2Fe2Sn square pyramids, edges with two equivalent O(7)Na2FeSn2 square pyramids,  an edgeedge with one O(1)Na2FeSn2 trigonal bipyramid,  an edgeedge with one O(5)Na2FeSn2 trigonal bipyramid, and edges with two equivalent O(6)Na2Fe2Sn trigonal bipyramids. In the eighth O site, O(8) is bonded to two equivalent Na(1), two equivalent Fe(1), and one Sn(1) atom to form ONa2Fe2Sn square pyramids that share corners with two equivalent O(2)Na2Fe2Sn trigonal bipyramids, corners with two equivalent O(6)Na2Fe2Sn trigonal bipyramids, corners with two equivalent O(5)Na2FeSn2 trigonal bipyramids, edges with two equivalent O(8)Na2Fe2Sn square pyramids, edges with two equivalent O(7)Na2FeSn2 square pyramids,  an edgeedge with one O(2)Na2Fe2Sn trigonal bipyramid,  an edgeedge with one O(6)Na2Fe2Sn trigonal bipyramid, and edges with two equivalent O(5)Na2FeSn2 trigonal bipyramids.