Ca2NdNbO6 crystallizes in the monoclinic Pc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form CaO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-42°. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(6), two equivalent O(1), and two equivalent O(5) atoms. Nd(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(4), one O(5), two equivalent O(2), and two equivalent O(6) atoms. Nb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NbO6 octahedra that share corners with six equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-42°. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Nd(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), two equivalent Nd(1), and one Nb(1) atom. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), one Nd(1), and one Nb(1) atom to form distorted corner-sharing OCa2NdNb tetrahedra. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), one Nd(1), and one Nb(1) atom to form distorted corner-sharing OCa2NdNb tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Nd(1), and one Nb(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), two equivalent Nd(1), and one Nb(1) atom.
Ca2NdNbO6 crystallizes in the monoclinic Pc space group. There are two inequivalent Ca sites. In the first Ca site, Ca(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form CaO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-42°. The Ca(1)-O(1) bond length is 2.33 Å. The Ca(1)-O(2) bond length is 2.34 Å. The Ca(1)-O(3) bond length is 2.35 Å. The Ca(1)-O(4) bond length is 2.34 Å. The Ca(1)-O(5) bond length is 2.28 Å. The Ca(1)-O(6) bond length is 2.31 Å. In the second Ca site, Ca(2) is bonded in a 8-coordinate geometry to one O(2), one O(3), one O(4), one O(6), two equivalent O(1), and two equivalent O(5) atoms. The Ca(2)-O(2) bond length is 2.39 Å. The Ca(2)-O(3) bond length is 2.44 Å. The Ca(2)-O(4) bond length is 2.35 Å. The Ca(2)-O(6) bond length is 2.38 Å. There is one shorter (2.67 Å) and one longer (3.04 Å) Ca(2)-O(1) bond length. There is one shorter (2.78 Å) and one longer (2.85 Å) Ca(2)-O(5) bond length. Nd(1) is bonded in a 8-coordinate geometry to one O(1), one O(3), one O(4), one O(5), two equivalent O(2), and two equivalent O(6) atoms. The Nd(1)-O(1) bond length is 2.36 Å. The Nd(1)-O(3) bond length is 2.33 Å. The Nd(1)-O(4) bond length is 2.42 Å. The Nd(1)-O(5) bond length is 2.35 Å. There is one shorter (2.63 Å) and one longer (3.05 Å) Nd(1)-O(2) bond length. There is one shorter (2.76 Å) and one longer (2.85 Å) Nd(1)-O(6) bond length. Nb(1) is bonded to one O(1), one O(2), one O(3), one O(4), one O(5), and one O(6) atom to form NbO6 octahedra that share corners with six equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 34-42°. The Nb(1)-O(1) bond length is 2.04 Å. The Nb(1)-O(2) bond length is 2.05 Å. The Nb(1)-O(3) bond length is 2.05 Å. The Nb(1)-O(4) bond length is 2.02 Å. The Nb(1)-O(5) bond length is 2.02 Å. The Nb(1)-O(6) bond length is 2.01 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Nd(1), and one Nb(1) atom. In the second O site, O(2) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), two equivalent Nd(1), and one Nb(1) atom. In the third O site, O(3) is bonded to one Ca(1), one Ca(2), one Nd(1), and one Nb(1) atom to form distorted corner-sharing OCa2NdNb tetrahedra. In the fourth O site, O(4) is bonded to one Ca(1), one Ca(2), one Nd(1), and one Nb(1) atom to form distorted corner-sharing OCa2NdNb tetrahedra. In the fifth O site, O(5) is bonded in a 5-coordinate geometry to one Ca(1), two equivalent Ca(2), one Nd(1), and one Nb(1) atom. In the sixth O site, O(6) is bonded in a 5-coordinate geometry to one Ca(1), one Ca(2), two equivalent Nd(1), and one Nb(1) atom.