Ca2Nd2Nb3FeO14 crystallizes in the monoclinic C2/m 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(5), and four equivalent O(3) atoms to form distorted CaO8 hexagonal bipyramids that share edges with two equivalent Ca(2)O8 hexagonal bipyramids, edges with four equivalent Nd(1)O8 hexagonal bipyramids, edges with two equivalent Nb(1)O6 octahedra, and edges with four equivalent Nb(2)O6 octahedra. In the second Ca site, Ca(2) is bonded to two equivalent O(1), two equivalent O(5), and four equivalent O(4) atoms to form distorted CaO8 hexagonal bipyramids that share edges with two equivalent Ca(1)O8 hexagonal bipyramids, edges with four equivalent Nd(1)O8 hexagonal bipyramids, edges with two equivalent Fe(1)O6 octahedra, and edges with four equivalent Nb(2)O6 octahedra. Nd(1) is bonded to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted NdO8 hexagonal bipyramids that share edges with two equivalent Ca(1)O8 hexagonal bipyramids, edges with two equivalent Ca(2)O8 hexagonal bipyramids, edges with two equivalent Nd(1)O8 hexagonal bipyramids, edges with two equivalent Nb(1)O6 octahedra, edges with two equivalent Nb(2)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, edges with two equivalent Ca(1)O8 hexagonal bipyramids, and edges with four equivalent Nd(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 44-48°. In the second Nb site, Nb(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, edges with two equivalent Ca(1)O8 hexagonal bipyramids, edges with two equivalent Ca(2)O8 hexagonal bipyramids, and edges with two equivalent Nd(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 42-46°. Fe(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, edges with two equivalent Ca(2)O8 hexagonal bipyramids, and edges with four equivalent Nd(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-48°. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), and two equivalent Nb(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Nd(1), one Nb(1), and one Fe(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Nd(1), one Nb(1), and one Nb(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ca(2), one Nd(1), one Nb(2), and one Fe(1) atom. In the fifth O site, O(5) is bonded to one Ca(1), one Ca(2), and two equivalent Nd(1) atoms to form corner-sharing OCa2Nd2 tetrahedra.
Ca2Nd2Nb3FeO14 crystallizes in the monoclinic C2/m 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(5), and four equivalent O(3) atoms to form distorted CaO8 hexagonal bipyramids that share edges with two equivalent Ca(2)O8 hexagonal bipyramids, edges with four equivalent Nd(1)O8 hexagonal bipyramids, edges with two equivalent Nb(1)O6 octahedra, and edges with four equivalent Nb(2)O6 octahedra. Both Ca(1)-O(1) bond lengths are 2.67 Å. Both Ca(1)-O(5) bond lengths are 2.24 Å. All Ca(1)-O(3) bond lengths are 2.68 Å. In the second Ca site, Ca(2) is bonded to two equivalent O(1), two equivalent O(5), and four equivalent O(4) atoms to form distorted CaO8 hexagonal bipyramids that share edges with two equivalent Ca(1)O8 hexagonal bipyramids, edges with four equivalent Nd(1)O8 hexagonal bipyramids, edges with two equivalent Fe(1)O6 octahedra, and edges with four equivalent Nb(2)O6 octahedra. Both Ca(2)-O(1) bond lengths are 2.63 Å. Both Ca(2)-O(5) bond lengths are 2.28 Å. All Ca(2)-O(4) bond lengths are 2.67 Å. Nd(1) is bonded to two equivalent O(2), two equivalent O(3), two equivalent O(4), and two equivalent O(5) atoms to form distorted NdO8 hexagonal bipyramids that share edges with two equivalent Ca(1)O8 hexagonal bipyramids, edges with two equivalent Ca(2)O8 hexagonal bipyramids, edges with two equivalent Nd(1)O8 hexagonal bipyramids, edges with two equivalent Nb(1)O6 octahedra, edges with two equivalent Nb(2)O6 octahedra, and edges with two equivalent Fe(1)O6 octahedra. Both Nd(1)-O(2) bond lengths are 2.62 Å. Both Nd(1)-O(3) bond lengths are 2.59 Å. Both Nd(1)-O(4) bond lengths are 2.60 Å. Both Nd(1)-O(5) bond lengths are 2.30 Å. There are two inequivalent Nb sites. In the first Nb site, Nb(1) is bonded to two equivalent O(2) and four equivalent O(3) atoms to form NbO6 octahedra that share corners with two equivalent Fe(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, edges with two equivalent Ca(1)O8 hexagonal bipyramids, and edges with four equivalent Nd(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 44-48°. Both Nb(1)-O(2) bond lengths are 1.99 Å. All Nb(1)-O(3) bond lengths are 2.02 Å. In the second Nb site, Nb(2) is bonded to two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms to form NbO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with two equivalent Nb(2)O6 octahedra, corners with two equivalent Fe(1)O6 octahedra, edges with two equivalent Ca(1)O8 hexagonal bipyramids, edges with two equivalent Ca(2)O8 hexagonal bipyramids, and edges with two equivalent Nd(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 42-46°. Both Nb(2)-O(1) bond lengths are 2.02 Å. Both Nb(2)-O(3) bond lengths are 2.03 Å. Both Nb(2)-O(4) bond lengths are 1.98 Å. Fe(1) is bonded to two equivalent O(2) and four equivalent O(4) atoms to form FeO6 octahedra that share corners with two equivalent Nb(1)O6 octahedra, corners with four equivalent Nb(2)O6 octahedra, edges with two equivalent Ca(2)O8 hexagonal bipyramids, and edges with four equivalent Nd(1)O8 hexagonal bipyramids. The corner-sharing octahedral tilt angles range from 46-48°. Both Fe(1)-O(2) bond lengths are 2.04 Å. All Fe(1)-O(4) bond lengths are 2.04 Å. There are five inequivalent O sites. In the first O site, O(1) is bonded in a 4-coordinate geometry to one Ca(1), one Ca(2), and two equivalent Nb(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Nd(1), one Nb(1), and one Fe(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to one Ca(1), one Nd(1), one Nb(1), and one Nb(2) atom. In the fourth O site, O(4) is bonded in a 4-coordinate geometry to one Ca(2), one Nd(1), one Nb(2), and one Fe(1) atom. In the fifth O site, O(5) is bonded to one Ca(1), one Ca(2), and two equivalent Nd(1) atoms to form corner-sharing OCa2Nd2 tetrahedra.