Ca3Fe4(SbO4)6 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(9) atoms to form distorted CaO8 hexagonal bipyramids that share corners with two equivalent Sb(2)O4 tetrahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Sb(1)O5 trigonal bipyramids, and edges with two equivalent Sb(3)O5 trigonal bipyramids. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(2), one O(6), one O(7), and two equivalent O(5) atoms. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(6), one O(7), one O(9), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with three equivalent Sb(2)O4 tetrahedra,  a cornercorner with one Sb(3)O5 trigonal bipyramid, corners with two equivalent Sb(1)O5 trigonal bipyramids,  an edgeedge with one Ca(1)O8 hexagonal bipyramid, and  an edgeedge with one Fe(1)O6 octahedra. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(12), one O(5), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Sb(2)O4 tetrahedra, corners with two equivalent Sb(1)O5 trigonal bipyramids, corners with three equivalent Sb(3)O5 trigonal bipyramids, and  an edgeedge with one Fe(2)O6 octahedra. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(10), one O(11), one O(2), one O(3), and one O(6) atom to form SbO5 trigonal bipyramids that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Sb(3)O5 trigonal bipyramid, and  an edgeedge with one Ca(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 34-54°. In the second Sb site, Sb(2) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form SbO4 tetrahedra that share  a cornercorner with one Ca(1)O8 hexagonal bipyramid, corners with two equivalent Fe(2)O6 octahedra, and corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-61°. In the third Sb site, Sb(3) is bonded to one O(2), one O(5), one O(9), and two equivalent O(12) atoms to form SbO5 trigonal bipyramids that share  a cornercorner with one Fe(1)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra,  a cornercorner with one Sb(1)O5 trigonal bipyramid,  an edgeedge with one Ca(1)O8 hexagonal bipyramid, and  an edgeedge with one Sb(3)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 37-60°. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Ca(1) and one Sb(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Sb(1), and one Sb(3) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1), one Fe(1), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one Sb(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(2), one Fe(2), and one Sb(3) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Ca(2), one Fe(1), and one Sb(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Ca(2), one Fe(1), and one Sb(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to two equivalent Fe(2) and one Sb(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Ca(1), one Fe(1), and one Sb(3) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Ca(2), one Fe(2), and one Sb(1) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal non-coplanar geometry to one Ca(2), one Fe(2), and one Sb(1) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Sb(3) atoms.
Ca3Fe4(SbO4)6 crystallizes in the triclinic P-1 space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to two equivalent O(1), two equivalent O(2), two equivalent O(3), and two equivalent O(9) atoms to form distorted CaO8 hexagonal bipyramids that share corners with two equivalent Sb(2)O4 tetrahedra, edges with two equivalent Fe(1)O6 octahedra, edges with two equivalent Sb(1)O5 trigonal bipyramids, and edges with two equivalent Sb(3)O5 trigonal bipyramids. Both Ca(1)-O(1) bond lengths are 2.33 Å. Both Ca(1)-O(2) bond lengths are 2.96 Å. Both Ca(1)-O(3) bond lengths are 2.25 Å. Both Ca(1)-O(9) bond lengths are 2.71 Å. In the second Ca site, Ca(2) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(2), one O(6), one O(7), and two equivalent O(5) atoms. The Ca(2)-O(10) bond length is 2.79 Å. The Ca(2)-O(11) bond length is 2.43 Å. The Ca(2)-O(2) bond length is 2.51 Å. The Ca(2)-O(6) bond length is 2.28 Å. The Ca(2)-O(7) bond length is 2.37 Å. There is one shorter (2.46 Å) and one longer (2.85 Å) Ca(2)-O(5) bond length. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded to one O(3), one O(6), one O(7), one O(9), and two equivalent O(4) atoms to form FeO6 octahedra that share corners with three equivalent Sb(2)O4 tetrahedra,  a cornercorner with one Sb(3)O5 trigonal bipyramid, corners with two equivalent Sb(1)O5 trigonal bipyramids,  an edgeedge with one Ca(1)O8 hexagonal bipyramid, and  an edgeedge with one Fe(1)O6 octahedra. The Fe(1)-O(3) bond length is 1.98 Å. The Fe(1)-O(6) bond length is 1.95 Å. The Fe(1)-O(7) bond length is 2.05 Å. The Fe(1)-O(9) bond length is 2.00 Å. There is one shorter (2.10 Å) and one longer (2.13 Å) Fe(1)-O(4) bond length. In the second Fe site, Fe(2) is bonded to one O(10), one O(11), one O(12), one O(5), and two equivalent O(8) atoms to form FeO6 octahedra that share corners with two equivalent Sb(2)O4 tetrahedra, corners with two equivalent Sb(1)O5 trigonal bipyramids, corners with three equivalent Sb(3)O5 trigonal bipyramids, and  an edgeedge with one Fe(2)O6 octahedra. The Fe(2)-O(10) bond length is 1.91 Å. The Fe(2)-O(11) bond length is 1.96 Å. The Fe(2)-O(12) bond length is 2.19 Å. The Fe(2)-O(5) bond length is 2.09 Å. Both Fe(2)-O(8) bond lengths are 2.08 Å. There are three inequivalent Sb sites. In the first Sb site, Sb(1) is bonded to one O(10), one O(11), one O(2), one O(3), and one O(6) atom to form SbO5 trigonal bipyramids that share corners with two equivalent Fe(1)O6 octahedra, corners with two equivalent Fe(2)O6 octahedra,  a cornercorner with one Sb(3)O5 trigonal bipyramid, and  an edgeedge with one Ca(1)O8 hexagonal bipyramid. The corner-sharing octahedral tilt angles range from 34-54°. The Sb(1)-O(10) bond length is 1.92 Å. The Sb(1)-O(11) bond length is 1.93 Å. The Sb(1)-O(2) bond length is 2.06 Å. The Sb(1)-O(3) bond length is 1.91 Å. The Sb(1)-O(6) bond length is 1.94 Å. In the second Sb site, Sb(2) is bonded to one O(1), one O(4), one O(7), and one O(8) atom to form SbO4 tetrahedra that share  a cornercorner with one Ca(1)O8 hexagonal bipyramid, corners with two equivalent Fe(2)O6 octahedra, and corners with three equivalent Fe(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-61°. The Sb(2)-O(1) bond length is 1.87 Å. The Sb(2)-O(4) bond length is 1.93 Å. The Sb(2)-O(7) bond length is 1.92 Å. The Sb(2)-O(8) bond length is 1.98 Å. In the third Sb site, Sb(3) is bonded to one O(2), one O(5), one O(9), and two equivalent O(12) atoms to form SbO5 trigonal bipyramids that share  a cornercorner with one Fe(1)O6 octahedra, corners with three equivalent Fe(2)O6 octahedra,  a cornercorner with one Sb(1)O5 trigonal bipyramid,  an edgeedge with one Ca(1)O8 hexagonal bipyramid, and  an edgeedge with one Sb(3)O5 trigonal bipyramid. The corner-sharing octahedral tilt angles range from 37-60°. The Sb(3)-O(2) bond length is 1.99 Å. The Sb(3)-O(5) bond length is 1.93 Å. The Sb(3)-O(9) bond length is 1.90 Å. There is one shorter (1.97 Å) and one longer (2.14 Å) Sb(3)-O(12) bond length. There are twelve inequivalent O sites. In the first O site, O(1) is bonded in a distorted bent 150 degrees geometry to one Ca(1) and one Sb(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), one Sb(1), and one Sb(3) atom. In the third O site, O(3) is bonded in a trigonal planar geometry to one Ca(1), one Fe(1), and one Sb(1) atom. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to two equivalent Fe(1) and one Sb(2) atom. In the fifth O site, O(5) is bonded in a 4-coordinate geometry to two equivalent Ca(2), one Fe(2), and one Sb(3) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Ca(2), one Fe(1), and one Sb(1) atom. In the seventh O site, O(7) is bonded in a trigonal planar geometry to one Ca(2), one Fe(1), and one Sb(2) atom. In the eighth O site, O(8) is bonded in a distorted trigonal planar geometry to two equivalent Fe(2) and one Sb(2) atom. In the ninth O site, O(9) is bonded in a 3-coordinate geometry to one Ca(1), one Fe(1), and one Sb(3) atom. In the tenth O site, O(10) is bonded in a distorted bent 150 degrees geometry to one Ca(2), one Fe(2), and one Sb(1) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal non-coplanar geometry to one Ca(2), one Fe(2), and one Sb(1) atom. In the twelfth O site, O(12) is bonded in a trigonal planar geometry to one Fe(2) and two equivalent Sb(3) atoms.