CaZrNbFeO7 crystallizes in the monoclinic Cc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted body-centered cubic geometry to one O(1), one O(10), one O(13), one O(14), one O(3), one O(4), one O(6), and one O(7) atom. In the second Ca site, Ca(2) is bonded in a distorted body-centered cubic geometry to one O(13), one O(14), one O(2), one O(3), one O(4), one O(5), one O(8), and one O(9) atom. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(14), one O(3), one O(5), one O(6), and one O(9) atom. In the second Zr site, Zr(2) is bonded in a 7-coordinate geometry to one O(10), one O(12), one O(13), one O(4), one O(5), one O(6), and one O(9) atom. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom to form NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-46°. In the second Nb site, Nb(2) is bonded to one O(1), one O(12), one O(2), one O(4), one O(5), and one O(8) atom to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-51°. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 4-coordinate geometry to one O(1), one O(13), one O(14), one O(7), and one O(8) atom. In the second Fe site, Fe(2) is bonded to one O(1), one O(11), one O(2), one O(3), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-51°. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Nb(2), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(2), one Nb(2), and one Fe(2) atom. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), one Zr(1), and one Fe(2) atom to form distorted OCa2ZrFe tetrahedra that share  a cornercorner with one O(6)CaZr2Fe tetrahedra, corners with two equivalent O(13)Ca2ZrFe tetrahedra, corners with two equivalent O(5)CaZr2Nb tetrahedra, corners with three equivalent O(14)Ca2ZrFe tetrahedra,  an edgeedge with one O(4)Ca2ZrNb tetrahedra,  an edgeedge with one O(6)CaZr2Fe tetrahedra, and  an edgeedge with one O(7)CaNbFe2 trigonal pyramid. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), one Zr(2), and one Nb(2) atom to form distorted OCa2ZrNb tetrahedra that share  a cornercorner with one O(5)CaZr2Nb tetrahedra, corners with two equivalent O(14)Ca2ZrFe tetrahedra, corners with two equivalent O(6)CaZr2Fe tetrahedra, corners with three equivalent O(13)Ca2ZrFe tetrahedra,  a cornercorner with one O(7)CaNbFe2 trigonal pyramid,  an edgeedge with one O(3)Ca2ZrFe tetrahedra, and  an edgeedge with one O(5)CaZr2Nb tetrahedra. In the fifth O site, O(5) is bonded to one Ca(2), one Zr(1), one Zr(2), and one Nb(2) atom to form distorted OCaZr2Nb tetrahedra that share  a cornercorner with one O(4)Ca2ZrNb tetrahedra, corners with two equivalent O(13)Ca2ZrFe tetrahedra, corners with two equivalent O(3)Ca2ZrFe tetrahedra,  an edgeedge with one O(14)Ca2ZrFe tetrahedra,  an edgeedge with one O(4)Ca2ZrNb tetrahedra, and  an edgeedge with one O(6)CaZr2Fe tetrahedra. In the sixth O site, O(6) is bonded to one Ca(1), one Zr(1), one Zr(2), and one Fe(2) atom to form distorted OCaZr2Fe tetrahedra that share  a cornercorner with one O(3)Ca2ZrFe tetrahedra, corners with two equivalent O(14)Ca2ZrFe tetrahedra, corners with two equivalent O(4)Ca2ZrNb tetrahedra, corners with two equivalent O(7)CaNbFe2 trigonal pyramids,  an edgeedge with one O(13)Ca2ZrFe tetrahedra,  an edgeedge with one O(3)Ca2ZrFe tetrahedra, and  an edgeedge with one O(5)CaZr2Nb tetrahedra. In the seventh O site, O(7) is bonded to one Ca(1), one Nb(1), one Fe(1), and one Fe(2) atom to form distorted OCaNbFe2 trigonal pyramids that share  a cornercorner with one O(4)Ca2ZrNb tetrahedra, corners with two equivalent O(14)Ca2ZrFe tetrahedra, corners with two equivalent O(6)CaZr2Fe tetrahedra,  an edgeedge with one O(13)Ca2ZrFe tetrahedra, and  an edgeedge with one O(3)Ca2ZrFe tetrahedra. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(2), one Nb(1), one Nb(2), and one Fe(1) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Ca(2), one Zr(1), one Zr(2), and one Nb(1) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Ca(1), one Zr(1), one Zr(2), and one Nb(1) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Zr(1), one Nb(1), and one Fe(2) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Zr(2), one Nb(1), and one Nb(2) atom. In the thirteenth O site, O(13) is bonded to one Ca(1), one Ca(2), one Zr(2), and one Fe(1) atom to form distorted OCa2ZrFe tetrahedra that share  a cornercorner with one O(14)Ca2ZrFe tetrahedra, corners with two equivalent O(3)Ca2ZrFe tetrahedra, corners with two equivalent O(5)CaZr2Nb tetrahedra, corners with three equivalent O(4)Ca2ZrNb tetrahedra,  an edgeedge with one O(14)Ca2ZrFe tetrahedra,  an edgeedge with one O(6)CaZr2Fe tetrahedra, and  an edgeedge with one O(7)CaNbFe2 trigonal pyramid. In the fourteenth O site, O(14) is bonded to one Ca(1), one Ca(2), one Zr(1), and one Fe(1) atom to form distorted OCa2ZrFe tetrahedra that share  a cornercorner with one O(13)Ca2ZrFe tetrahedra, corners with two equivalent O(4)Ca2ZrNb tetrahedra, corners with two equivalent O(6)CaZr2Fe tetrahedra, corners with three equivalent O(3)Ca2ZrFe tetrahedra, corners with two equivalent O(7)CaNbFe2 trigonal pyramids,  an edgeedge with one O(13)Ca2ZrFe tetrahedra, and  an edgeedge with one O(5)CaZr2Nb tetrahedra.
CaZrNbFeO7 crystallizes in the monoclinic Cc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded in a distorted body-centered cubic geometry to one O(1), one O(10), one O(13), one O(14), one O(3), one O(4), one O(6), and one O(7) atom. The Ca(1)-O(1) bond length is 2.48 Å. The Ca(1)-O(10) bond length is 2.66 Å. The Ca(1)-O(13) bond length is 2.47 Å. The Ca(1)-O(14) bond length is 2.46 Å. The Ca(1)-O(3) bond length is 2.48 Å. The Ca(1)-O(4) bond length is 2.49 Å. The Ca(1)-O(6) bond length is 2.52 Å. The Ca(1)-O(7) bond length is 2.49 Å. In the second Ca site, Ca(2) is bonded in a distorted body-centered cubic geometry to one O(13), one O(14), one O(2), one O(3), one O(4), one O(5), one O(8), and one O(9) atom. The Ca(2)-O(13) bond length is 2.41 Å. The Ca(2)-O(14) bond length is 2.47 Å. The Ca(2)-O(2) bond length is 2.44 Å. The Ca(2)-O(3) bond length is 2.45 Å. The Ca(2)-O(4) bond length is 2.60 Å. The Ca(2)-O(5) bond length is 2.54 Å. The Ca(2)-O(8) bond length is 2.59 Å. The Ca(2)-O(9) bond length is 2.64 Å. There are two inequivalent Zr sites. In the first Zr site, Zr(1) is bonded in a 7-coordinate geometry to one O(10), one O(11), one O(14), one O(3), one O(5), one O(6), and one O(9) atom. The Zr(1)-O(10) bond length is 2.17 Å. The Zr(1)-O(11) bond length is 2.14 Å. The Zr(1)-O(14) bond length is 2.21 Å. The Zr(1)-O(3) bond length is 2.06 Å. The Zr(1)-O(5) bond length is 2.11 Å. The Zr(1)-O(6) bond length is 2.29 Å. The Zr(1)-O(9) bond length is 2.58 Å. In the second Zr site, Zr(2) is bonded in a 7-coordinate geometry to one O(10), one O(12), one O(13), one O(4), one O(5), one O(6), and one O(9) atom. The Zr(2)-O(10) bond length is 2.65 Å. The Zr(2)-O(12) bond length is 2.18 Å. The Zr(2)-O(13) bond length is 2.12 Å. The Zr(2)-O(4) bond length is 2.14 Å. The Zr(2)-O(5) bond length is 2.40 Å. The Zr(2)-O(6) bond length is 2.04 Å. The Zr(2)-O(9) bond length is 2.10 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to one O(10), one O(11), one O(12), one O(7), one O(8), and one O(9) atom to form NbO6 octahedra that share corners with two equivalent Nb(2)O6 octahedra and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 43-46°. The Nb(1)-O(10) bond length is 1.93 Å. The Nb(1)-O(11) bond length is 1.98 Å. The Nb(1)-O(12) bond length is 1.97 Å. The Nb(1)-O(7) bond length is 2.03 Å. The Nb(1)-O(8) bond length is 2.06 Å. The Nb(1)-O(9) bond length is 2.01 Å. In the second Nb site, Nb(2) is bonded to one O(1), one O(12), one O(2), one O(4), one O(5), and one O(8) atom to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Fe(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-51°. The Nb(2)-O(1) bond length is 2.10 Å. The Nb(2)-O(12) bond length is 2.14 Å. The Nb(2)-O(2) bond length is 1.88 Å. The Nb(2)-O(4) bond length is 2.00 Å. The Nb(2)-O(5) bond length is 2.06 Å. The Nb(2)-O(8) bond length is 1.92 Å. There are two inequivalent Fe sites. In the first Fe site, Fe(1) is bonded in a 4-coordinate geometry to one O(1), one O(13), one O(14), one O(7), and one O(8) atom. The Fe(1)-O(1) bond length is 2.01 Å. The Fe(1)-O(13) bond length is 1.89 Å. The Fe(1)-O(14) bond length is 1.87 Å. The Fe(1)-O(7) bond length is 1.99 Å. The Fe(1)-O(8) bond length is 2.60 Å. In the second Fe site, Fe(2) is bonded to one O(1), one O(11), one O(2), one O(3), one O(6), and one O(7) atom to form FeO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra and corners with two equivalent Nb(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 32-51°. The Fe(2)-O(1) bond length is 2.06 Å. The Fe(2)-O(11) bond length is 2.01 Å. The Fe(2)-O(2) bond length is 1.98 Å. The Fe(2)-O(3) bond length is 2.02 Å. The Fe(2)-O(6) bond length is 2.08 Å. The Fe(2)-O(7) bond length is 2.04 Å. There are fourteen inequivalent O sites. In the first O site, O(1) is bonded in a distorted rectangular see-saw-like geometry to one Ca(1), one Nb(2), one Fe(1), and one Fe(2) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Ca(2), one Nb(2), and one Fe(2) atom. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), one Zr(1), and one Fe(2) atom to form distorted OCa2ZrFe tetrahedra that share  a cornercorner with one O(6)CaZr2Fe tetrahedra, corners with two equivalent O(13)Ca2ZrFe tetrahedra, corners with two equivalent O(5)CaZr2Nb tetrahedra, corners with three equivalent O(14)Ca2ZrFe tetrahedra,  an edgeedge with one O(4)Ca2ZrNb tetrahedra,  an edgeedge with one O(6)CaZr2Fe tetrahedra, and  an edgeedge with one O(7)CaNbFe2 trigonal pyramid. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), one Zr(2), and one Nb(2) atom to form distorted OCa2ZrNb tetrahedra that share  a cornercorner with one O(5)CaZr2Nb tetrahedra, corners with two equivalent O(14)Ca2ZrFe tetrahedra, corners with two equivalent O(6)CaZr2Fe tetrahedra, corners with three equivalent O(13)Ca2ZrFe tetrahedra,  a cornercorner with one O(7)CaNbFe2 trigonal pyramid,  an edgeedge with one O(3)Ca2ZrFe tetrahedra, and  an edgeedge with one O(5)CaZr2Nb tetrahedra. In the fifth O site, O(5) is bonded to one Ca(2), one Zr(1), one Zr(2), and one Nb(2) atom to form distorted OCaZr2Nb tetrahedra that share  a cornercorner with one O(4)Ca2ZrNb tetrahedra, corners with two equivalent O(13)Ca2ZrFe tetrahedra, corners with two equivalent O(3)Ca2ZrFe tetrahedra,  an edgeedge with one O(14)Ca2ZrFe tetrahedra,  an edgeedge with one O(4)Ca2ZrNb tetrahedra, and  an edgeedge with one O(6)CaZr2Fe tetrahedra. In the sixth O site, O(6) is bonded to one Ca(1), one Zr(1), one Zr(2), and one Fe(2) atom to form distorted OCaZr2Fe tetrahedra that share  a cornercorner with one O(3)Ca2ZrFe tetrahedra, corners with two equivalent O(14)Ca2ZrFe tetrahedra, corners with two equivalent O(4)Ca2ZrNb tetrahedra, corners with two equivalent O(7)CaNbFe2 trigonal pyramids,  an edgeedge with one O(13)Ca2ZrFe tetrahedra,  an edgeedge with one O(3)Ca2ZrFe tetrahedra, and  an edgeedge with one O(5)CaZr2Nb tetrahedra. In the seventh O site, O(7) is bonded to one Ca(1), one Nb(1), one Fe(1), and one Fe(2) atom to form distorted OCaNbFe2 trigonal pyramids that share  a cornercorner with one O(4)Ca2ZrNb tetrahedra, corners with two equivalent O(14)Ca2ZrFe tetrahedra, corners with two equivalent O(6)CaZr2Fe tetrahedra,  an edgeedge with one O(13)Ca2ZrFe tetrahedra, and  an edgeedge with one O(3)Ca2ZrFe tetrahedra. In the eighth O site, O(8) is bonded in a 4-coordinate geometry to one Ca(2), one Nb(1), one Nb(2), and one Fe(1) atom. In the ninth O site, O(9) is bonded in a 4-coordinate geometry to one Ca(2), one Zr(1), one Zr(2), and one Nb(1) atom. In the tenth O site, O(10) is bonded in a 4-coordinate geometry to one Ca(1), one Zr(1), one Zr(2), and one Nb(1) atom. In the eleventh O site, O(11) is bonded in a distorted trigonal planar geometry to one Zr(1), one Nb(1), and one Fe(2) atom. In the twelfth O site, O(12) is bonded in a distorted trigonal non-coplanar geometry to one Zr(2), one Nb(1), and one Nb(2) atom. In the thirteenth O site, O(13) is bonded to one Ca(1), one Ca(2), one Zr(2), and one Fe(1) atom to form distorted OCa2ZrFe tetrahedra that share  a cornercorner with one O(14)Ca2ZrFe tetrahedra, corners with two equivalent O(3)Ca2ZrFe tetrahedra, corners with two equivalent O(5)CaZr2Nb tetrahedra, corners with three equivalent O(4)Ca2ZrNb tetrahedra,  an edgeedge with one O(14)Ca2ZrFe tetrahedra,  an edgeedge with one O(6)CaZr2Fe tetrahedra, and  an edgeedge with one O(7)CaNbFe2 trigonal pyramid. In the fourteenth O site, O(14) is bonded to one Ca(1), one Ca(2), one Zr(1), and one Fe(1) atom to form distorted OCa2ZrFe tetrahedra that share  a cornercorner with one O(13)Ca2ZrFe tetrahedra, corners with two equivalent O(4)Ca2ZrNb tetrahedra, corners with two equivalent O(6)CaZr2Fe tetrahedra, corners with three equivalent O(3)Ca2ZrFe tetrahedra, corners with two equivalent O(7)CaNbFe2 trigonal pyramids,  an edgeedge with one O(13)Ca2ZrFe tetrahedra, and  an edgeedge with one O(5)CaZr2Nb tetrahedra.