SrCaNdSbO6 crystallizes in the tetragonal P-4n2 space group. Sr(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. Ca(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CaO6 octahedra that share corners with six equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-34°. Nd(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. Sb(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with six equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-34°. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), one Ca(1), two equivalent Nd(1), and one Sb(1) atom to form distorted OSr2CaNd2Sb octahedra that share corners with six equivalent O(1)Sr2CaNd2Sb octahedra, corners with eight equivalent O(2)SrCaNdSb tetrahedra, edges with four equivalent O(1)Sr2CaNd2Sb octahedra, and edges with eight equivalent O(2)SrCaNdSb tetrahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the second O site, O(2) is bonded to one Sr(1), one Ca(1), one Nd(1), and one Sb(1) atom to form distorted OSrCaNdSb tetrahedra that share corners with four equivalent O(1)Sr2CaNd2Sb octahedra, corners with ten equivalent O(2)SrCaNdSb tetrahedra, edges with four equivalent O(1)Sr2CaNd2Sb octahedra, and  an edgeedge with one O(2)SrCaNdSb tetrahedra. The corner-sharing octahedral tilt angles range from 65-68°.
SrCaNdSbO6 crystallizes in the tetragonal P-4n2 space group. Sr(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Sr(1)-O(1) bond lengths are 2.91 Å. All Sr(1)-O(2) bond lengths are 2.65 Å. Ca(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form CaO6 octahedra that share corners with six equivalent Sb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-34°. Both Ca(1)-O(1) bond lengths are 2.22 Å. All Ca(1)-O(2) bond lengths are 2.30 Å. Nd(1) is bonded in a distorted body-centered cubic geometry to four equivalent O(1) and four equivalent O(2) atoms. All Nd(1)-O(1) bond lengths are 2.91 Å. All Nd(1)-O(2) bond lengths are 2.47 Å. Sb(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form SbO6 octahedra that share corners with six equivalent Ca(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 0-34°. Both Sb(1)-O(1) bond lengths are 2.00 Å. All Sb(1)-O(2) bond lengths are 2.01 Å. There are two inequivalent O sites. In the first O site, O(1) is bonded to two equivalent Sr(1), one Ca(1), two equivalent Nd(1), and one Sb(1) atom to form distorted OSr2CaNd2Sb octahedra that share corners with six equivalent O(1)Sr2CaNd2Sb octahedra, corners with eight equivalent O(2)SrCaNdSb tetrahedra, edges with four equivalent O(1)Sr2CaNd2Sb octahedra, and edges with eight equivalent O(2)SrCaNdSb tetrahedra. The corner-sharing octahedral tilt angles range from 0-4°. In the second O site, O(2) is bonded to one Sr(1), one Ca(1), one Nd(1), and one Sb(1) atom to form distorted OSrCaNdSb tetrahedra that share corners with four equivalent O(1)Sr2CaNd2Sb octahedra, corners with ten equivalent O(2)SrCaNdSb tetrahedra, edges with four equivalent O(1)Sr2CaNd2Sb octahedra, and  an edgeedge with one O(2)SrCaNdSb tetrahedra. The corner-sharing octahedral tilt angles range from 65-68°.