Ta2NiZn2O8 crystallizes in the triclinic P-1 space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(8) atom to form distorted TaO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra and edges with two equivalent Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-55°. In the second Ta site, Ta(2) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form distorted TaO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra and edges with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-55°. Ni(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with four equivalent Ta(1)O6 octahedra, corners with four equivalent Ta(2)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-55°. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a distorted see-saw-like geometry to one O(5), one O(7), and two equivalent O(8) atoms. In the second Zn site, Zn(2) is bonded in a distorted see-saw-like geometry to one O(6), one O(8), and two equivalent O(7) atoms. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ta(1), one Ta(2), and one Ni(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ta(1), one Ta(2), and one Ni(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ta(1) and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ta(2) and two equivalent Ni(1) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Zn(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Zn(2) atom. In the seventh O site, O(7) is bonded to one Ta(2), one Zn(1), and two equivalent Zn(2) atoms to form a mixture of edge and corner-sharing OTaZn3 trigonal pyramids. In the eighth O site, O(8) is bonded to one Ta(1), one Zn(2), and two equivalent Zn(1) atoms to form a mixture of edge and corner-sharing OTaZn3 trigonal pyramids.
Ta2NiZn2O8 crystallizes in the triclinic P-1 space group. There are two inequivalent Ta sites. In the first Ta site, Ta(1) is bonded to one O(1), one O(2), one O(3), one O(5), one O(6), and one O(8) atom to form distorted TaO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra and edges with two equivalent Ta(2)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-55°. The Ta(1)-O(1) bond length is 2.00 Å. The Ta(1)-O(2) bond length is 2.03 Å. The Ta(1)-O(3) bond length is 1.86 Å. The Ta(1)-O(5) bond length is 2.02 Å. The Ta(1)-O(6) bond length is 2.23 Å. The Ta(1)-O(8) bond length is 2.03 Å. In the second Ta site, Ta(2) is bonded to one O(1), one O(2), one O(4), one O(5), one O(6), and one O(7) atom to form distorted TaO6 octahedra that share corners with four equivalent Ni(1)O6 octahedra and edges with two equivalent Ta(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-55°. The Ta(2)-O(1) bond length is 2.03 Å. The Ta(2)-O(2) bond length is 1.99 Å. The Ta(2)-O(4) bond length is 1.85 Å. The Ta(2)-O(5) bond length is 2.22 Å. The Ta(2)-O(6) bond length is 2.02 Å. The Ta(2)-O(7) bond length is 2.03 Å. Ni(1) is bonded to one O(1), one O(2), two equivalent O(3), and two equivalent O(4) atoms to form NiO6 octahedra that share corners with four equivalent Ta(1)O6 octahedra, corners with four equivalent Ta(2)O6 octahedra, and edges with two equivalent Ni(1)O6 octahedra. The corner-sharing octahedral tilt angles range from 49-55°. The Ni(1)-O(1) bond length is 2.16 Å. The Ni(1)-O(2) bond length is 2.16 Å. There is one shorter (2.09 Å) and one longer (2.10 Å) Ni(1)-O(3) bond length. There is one shorter (2.09 Å) and one longer (2.10 Å) Ni(1)-O(4) bond length. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a distorted see-saw-like geometry to one O(5), one O(7), and two equivalent O(8) atoms. The Zn(1)-O(5) bond length is 1.96 Å. The Zn(1)-O(7) bond length is 1.98 Å. There is one shorter (2.02 Å) and one longer (2.13 Å) Zn(1)-O(8) bond length. In the second Zn site, Zn(2) is bonded in a distorted see-saw-like geometry to one O(6), one O(8), and two equivalent O(7) atoms. The Zn(2)-O(6) bond length is 1.97 Å. The Zn(2)-O(8) bond length is 1.97 Å. There is one shorter (2.02 Å) and one longer (2.12 Å) Zn(2)-O(7) bond length. There are eight inequivalent O sites. In the first O site, O(1) is bonded in a trigonal planar geometry to one Ta(1), one Ta(2), and one Ni(1) atom. In the second O site, O(2) is bonded in a trigonal planar geometry to one Ta(1), one Ta(2), and one Ni(1) atom. In the third O site, O(3) is bonded in a distorted trigonal planar geometry to one Ta(1) and two equivalent Ni(1) atoms. In the fourth O site, O(4) is bonded in a distorted trigonal planar geometry to one Ta(2) and two equivalent Ni(1) atoms. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Zn(1) atom. In the sixth O site, O(6) is bonded in a distorted trigonal planar geometry to one Ta(1), one Ta(2), and one Zn(2) atom. In the seventh O site, O(7) is bonded to one Ta(2), one Zn(1), and two equivalent Zn(2) atoms to form a mixture of edge and corner-sharing OTaZn3 trigonal pyramids. In the eighth O site, O(8) is bonded to one Ta(1), one Zn(2), and two equivalent Zn(1) atoms to form a mixture of edge and corner-sharing OTaZn3 trigonal pyramids.