BaZn(SeO3)4 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded to four equivalent O(3) and eight equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(1)O12 cuboctahedra and faces with eight equivalent Se(1)O6 octahedra. Zn(1) is bonded in a distorted body-centered cubic geometry to eight equivalent O(1) atoms. Se(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form SeO6 octahedra that share corners with six equivalent Se(1)O6 octahedra and faces with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-8°. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted square co-planar geometry to one Ba(1), one Zn(1), and two equivalent Se(1) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent Se(1) atoms. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Ba(1) and two equivalent Se(1) atoms.
BaZn(SeO3)4 crystallizes in the tetragonal P4/mmm space group. Ba(1) is bonded to four equivalent O(3) and eight equivalent O(1) atoms to form BaO12 cuboctahedra that share corners with four equivalent Ba(1)O12 cuboctahedra and faces with eight equivalent Se(1)O6 octahedra. All Ba(1)-O(3) bond lengths are 2.70 Å. All Ba(1)-O(1) bond lengths are 2.87 Å. Zn(1) is bonded in a distorted body-centered cubic geometry to eight equivalent O(1) atoms. All Zn(1)-O(1) bond lengths are 2.48 Å. Se(1) is bonded to one O(2), one O(3), and four equivalent O(1) atoms to form SeO6 octahedra that share corners with six equivalent Se(1)O6 octahedra and faces with two equivalent Ba(1)O12 cuboctahedra. The corner-sharing octahedral tilt angles range from 0-8°. The Se(1)-O(2) bond length is 1.80 Å. The Se(1)-O(3) bond length is 1.95 Å. All Se(1)-O(1) bond lengths are 1.91 Å. There are three inequivalent O sites. In the first O site, O(1) is bonded in a distorted square co-planar geometry to one Ba(1), one Zn(1), and two equivalent Se(1) atoms. In the second O site, O(2) is bonded in a linear geometry to two equivalent Se(1) atoms. In the third O site, O(3) is bonded in a square co-planar geometry to two equivalent Ba(1) and two equivalent Se(1) atoms.