NaNdNb4O12 crystallizes in the orthorhombic Cmmm space group. Na(1) is bonded to four equivalent O(2) and four equivalent O(3) atoms to form distorted NaO8 cuboctahedra that share corners with four equivalent Na(1)O8 cuboctahedra, corners with four equivalent Nd(1)O12 cuboctahedra, and edges with eight equivalent Nb(1)O6 octahedra. Nd(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(4) atoms to form NdO12 cuboctahedra that share corners with four equivalent Na(1)O8 cuboctahedra, corners with four equivalent Nd(1)O12 cuboctahedra, and faces with eight equivalent Nb(1)O6 octahedra. Nb(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra, edges with two equivalent Na(1)O8 cuboctahedra, and faces with two equivalent Nd(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-14°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Nd(1) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a distorted linear geometry to one Na(1), one Nd(1), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted square co-planar geometry to two equivalent Na(1) and two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded in a distorted linear geometry to two equivalent Nd(1) and two equivalent Nb(1) atoms.
NaNdNb4O12 crystallizes in the orthorhombic Cmmm space group. Na(1) is bonded to four equivalent O(2) and four equivalent O(3) atoms to form distorted NaO8 cuboctahedra that share corners with four equivalent Na(1)O8 cuboctahedra, corners with four equivalent Nd(1)O12 cuboctahedra, and edges with eight equivalent Nb(1)O6 octahedra. All Na(1)-O(2) bond lengths are 2.83 Å. All Na(1)-O(3) bond lengths are 2.82 Å. Nd(1) is bonded to four equivalent O(1), four equivalent O(2), and four equivalent O(4) atoms to form NdO12 cuboctahedra that share corners with four equivalent Na(1)O8 cuboctahedra, corners with four equivalent Nd(1)O12 cuboctahedra, and faces with eight equivalent Nb(1)O6 octahedra. All Nd(1)-O(1) bond lengths are 2.59 Å. All Nd(1)-O(2) bond lengths are 2.82 Å. All Nd(1)-O(4) bond lengths are 2.82 Å. Nb(1) is bonded to one O(3), one O(4), two equivalent O(1), and two equivalent O(2) atoms to form NbO6 octahedra that share corners with six equivalent Nb(1)O6 octahedra, edges with two equivalent Na(1)O8 cuboctahedra, and faces with two equivalent Nd(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-14°. The Nb(1)-O(3) bond length is 1.98 Å. The Nb(1)-O(4) bond length is 2.02 Å. Both Nb(1)-O(1) bond lengths are 2.01 Å. Both Nb(1)-O(2) bond lengths are 1.99 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a 3-coordinate geometry to one Nd(1) and two equivalent Nb(1) atoms. In the second O site, O(2) is bonded in a distorted linear geometry to one Na(1), one Nd(1), and two equivalent Nb(1) atoms. In the third O site, O(3) is bonded in a distorted square co-planar geometry to two equivalent Na(1) and two equivalent Nb(1) atoms. In the fourth O site, O(4) is bonded in a distorted linear geometry to two equivalent Nd(1) and two equivalent Nb(1) atoms.