Nb2Zn2BiO8 crystallizes in the monoclinic C2/c space group. Nb(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form distorted NbO6 octahedra that share corners with four equivalent Bi(1)O6 octahedra, corners with five equivalent Zn(1)O4 tetrahedra, and edges with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-62°. Zn(1) is bonded to one O(3) and three equivalent O(4) atoms to form distorted ZnO4 tetrahedra that share corners with five equivalent Nb(1)O6 octahedra, corners with four equivalent Zn(1)O4 tetrahedra, and  an edgeedge with one Zn(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-79°. Bi(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form distorted BiO6 octahedra that share corners with eight equivalent Nb(1)O6 octahedra and edges with two equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-62°. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Nb(1) and one Bi(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Nb(1) and one Zn(1) atom. In the fourth O site, O(4) is bonded to one Nb(1) and three equivalent Zn(1) atoms to form a mixture of corner and edge-sharing ONbZn3 trigonal pyramids.
Nb2Zn2BiO8 crystallizes in the monoclinic C2/c space group. Nb(1) is bonded to one O(2), one O(4), two equivalent O(1), and two equivalent O(3) atoms to form distorted NbO6 octahedra that share corners with four equivalent Bi(1)O6 octahedra, corners with five equivalent Zn(1)O4 tetrahedra, and edges with two equivalent Nb(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-62°. The Nb(1)-O(2) bond length is 1.94 Å. The Nb(1)-O(4) bond length is 2.07 Å. There is one shorter (2.04 Å) and one longer (2.06 Å) Nb(1)-O(1) bond length. There is one shorter (2.06 Å) and one longer (2.23 Å) Nb(1)-O(3) bond length. Zn(1) is bonded to one O(3) and three equivalent O(4) atoms to form distorted ZnO4 tetrahedra that share corners with five equivalent Nb(1)O6 octahedra, corners with four equivalent Zn(1)O4 tetrahedra, and  an edgeedge with one Zn(1)O4 tetrahedra. The corner-sharing octahedral tilt angles range from 53-79°. The Zn(1)-O(3) bond length is 1.98 Å. There are a spread of Zn(1)-O(4) bond distances ranging from 2.01-2.12 Å. Bi(1) is bonded to two equivalent O(1) and four equivalent O(2) atoms to form distorted BiO6 octahedra that share corners with eight equivalent Nb(1)O6 octahedra and edges with two equivalent Bi(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 37-62°. Both Bi(1)-O(1) bond lengths are 2.38 Å. All Bi(1)-O(2) bond lengths are 2.39 Å. There are four inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to two equivalent Nb(1) and one Bi(1) atom. In the second O site, O(2) is bonded in a 3-coordinate geometry to one Nb(1) and two equivalent Bi(1) atoms. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Nb(1) and one Zn(1) atom. In the fourth O site, O(4) is bonded to one Nb(1) and three equivalent Zn(1) atoms to form a mixture of corner and edge-sharing ONbZn3 trigonal pyramids.