Ti3Zn3(AsO4)4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(7), and one O(8) atom. In the second Ti site, Ti(2) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(7) atoms to form TiO6 octahedra that share corners with two equivalent As(2)O5 trigonal bipyramids and edges with two equivalent As(2)O5 trigonal bipyramids. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 5-coordinate geometry to one O(1), one O(5), one O(7), and two equivalent O(3) atoms. In the second Zn site, Zn(2) is bonded in a square co-planar geometry to two equivalent O(6) and two equivalent O(8) atoms. There are two inequivalent As sites. In the first As site, As(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(4), and one O(6) atom. In the second As site, As(2) is bonded to one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form AsO5 trigonal bipyramids that share  a cornercorner with one Ti(2)O6 octahedra and  an edgeedge with one Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles are 70°. There are eight inequivalent O sites. In the first O site, O(7) is bonded to one Ti(1), one Ti(2), one Zn(1), and one As(2) atom to form a mixture of distorted corner and edge-sharing OTi2ZnAs trigonal pyramids. In the second O site, O(8) is bonded in a bent 120 degrees geometry to one Ti(1) and one Zn(2) atom. In the third O site, O(1) is bonded in a trigonal planar geometry to one Ti(1), one Zn(1), and one As(1) atom. In the fourth O site, O(2) is bonded in a trigonal non-coplanar geometry to one Ti(1), one Ti(2), and one As(2) atom. In the fifth O site, O(3) is bonded in a trigonal non-coplanar geometry to two equivalent Zn(1) and one As(2) atom. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one Ti(1) and one As(1) atom. In the seventh O site, O(5) is bonded to one Ti(1), one Ti(2), one Zn(1), and one As(2) atom to form a mixture of distorted corner and edge-sharing OTi2ZnAs trigonal pyramids. In the eighth O site, O(6) is bonded in a distorted trigonal planar geometry to one Zn(2), one As(1), and one As(2) atom.
Ti3Zn3(AsO4)4 crystallizes in the monoclinic P2_1/c space group. There are two inequivalent Ti sites. In the first Ti site, Ti(1) is bonded in a 6-coordinate geometry to one O(1), one O(2), one O(4), one O(5), one O(7), and one O(8) atom. The Ti(1)-O(1) bond length is 2.06 Å. The Ti(1)-O(2) bond length is 2.08 Å. The Ti(1)-O(4) bond length is 1.88 Å. The Ti(1)-O(5) bond length is 2.55 Å. The Ti(1)-O(7) bond length is 2.05 Å. The Ti(1)-O(8) bond length is 1.73 Å. In the second Ti site, Ti(2) is bonded to two equivalent O(2), two equivalent O(5), and two equivalent O(7) atoms to form TiO6 octahedra that share corners with two equivalent As(2)O5 trigonal bipyramids and edges with two equivalent As(2)O5 trigonal bipyramids. Both Ti(2)-O(2) bond lengths are 2.03 Å. Both Ti(2)-O(5) bond lengths are 2.07 Å. Both Ti(2)-O(7) bond lengths are 1.94 Å. There are two inequivalent Zn sites. In the first Zn site, Zn(1) is bonded in a 5-coordinate geometry to one O(1), one O(5), one O(7), and two equivalent O(3) atoms. The Zn(1)-O(1) bond length is 1.98 Å. The Zn(1)-O(5) bond length is 2.06 Å. The Zn(1)-O(7) bond length is 2.44 Å. There is one shorter (1.98 Å) and one longer (2.03 Å) Zn(1)-O(3) bond length. In the second Zn site, Zn(2) is bonded in a square co-planar geometry to two equivalent O(6) and two equivalent O(8) atoms. Both Zn(2)-O(6) bond lengths are 2.20 Å. Both Zn(2)-O(8) bond lengths are 1.86 Å. There are two inequivalent As sites. In the first As site, As(1) is bonded in a distorted trigonal non-coplanar geometry to one O(1), one O(4), and one O(6) atom. The As(1)-O(1) bond length is 1.82 Å. The As(1)-O(4) bond length is 1.81 Å. The As(1)-O(6) bond length is 1.92 Å. In the second As site, As(2) is bonded to one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form AsO5 trigonal bipyramids that share  a cornercorner with one Ti(2)O6 octahedra and  an edgeedge with one Ti(2)O6 octahedra. The corner-sharing octahedral tilt angles are 70°. The As(2)-O(2) bond length is 2.14 Å. The As(2)-O(3) bond length is 1.78 Å. The As(2)-O(5) bond length is 1.88 Å. The As(2)-O(6) bond length is 1.94 Å. The As(2)-O(7) bond length is 2.05 Å. There are eight inequivalent O sites. In the first O site, O(7) is bonded to one Ti(1), one Ti(2), one Zn(1), and one As(2) atom to form a mixture of distorted corner and edge-sharing OTi2ZnAs trigonal pyramids. In the second O site, O(8) is bonded in a bent 120 degrees geometry to one Ti(1) and one Zn(2) atom. In the third O site, O(1) is bonded in a trigonal planar geometry to one Ti(1), one Zn(1), and one As(1) atom. In the fourth O site, O(2) is bonded in a trigonal non-coplanar geometry to one Ti(1), one Ti(2), and one As(2) atom. In the fifth O site, O(3) is bonded in a trigonal non-coplanar geometry to two equivalent Zn(1) and one As(2) atom. In the sixth O site, O(4) is bonded in a bent 150 degrees geometry to one Ti(1) and one As(1) atom. In the seventh O site, O(5) is bonded to one Ti(1), one Ti(2), one Zn(1), and one As(2) atom to form a mixture of distorted corner and edge-sharing OTi2ZnAs trigonal pyramids. In the eighth O site, O(6) is bonded in a distorted trigonal planar geometry to one Zn(2), one As(1), and one As(2) atom.