BaCu(SeO3)2 crystallizes in the orthorhombic Pmn2_1 space group. Ba(1) is bonded in a 11-coordinate geometry to one O(5), two equivalent O(1), two equivalent O(2), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. Cu(1) is bonded to one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form distorted corner-sharing CuO5 square pyramids. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one O(5) and two equivalent O(3) atoms. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(7) atom. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one O(4) and two equivalent O(6) atoms. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ba(1) and one Se(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Cu(1), and one Se(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Cu(1), and one Se(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to two equivalent Cu(1) and one Se(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Ba(1) and one Se(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Cu(1), and one Se(3) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Cu(1), and one Se(2) atom.
BaCu(SeO3)2 crystallizes in the orthorhombic Pmn2_1 space group. Ba(1) is bonded in a 11-coordinate geometry to one O(5), two equivalent O(1), two equivalent O(2), two equivalent O(3), two equivalent O(6), and two equivalent O(7) atoms. The Ba(1)-O(5) bond length is 2.88 Å. There is one shorter (2.80 Å) and one longer (2.84 Å) Ba(1)-O(1) bond length. There is one shorter (2.85 Å) and one longer (2.97 Å) Ba(1)-O(2) bond length. There is one shorter (2.89 Å) and one longer (3.31 Å) Ba(1)-O(3) bond length. There is one shorter (3.12 Å) and one longer (3.22 Å) Ba(1)-O(6) bond length. There is one shorter (2.94 Å) and one longer (3.22 Å) Ba(1)-O(7) bond length. Cu(1) is bonded to one O(2), one O(3), one O(4), one O(6), and one O(7) atom to form distorted corner-sharing CuO5 square pyramids. The Cu(1)-O(2) bond length is 2.04 Å. The Cu(1)-O(3) bond length is 1.96 Å. The Cu(1)-O(4) bond length is 1.99 Å. The Cu(1)-O(6) bond length is 2.37 Å. The Cu(1)-O(7) bond length is 1.95 Å. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one O(5) and two equivalent O(3) atoms. The Se(1)-O(5) bond length is 1.70 Å. Both Se(1)-O(3) bond lengths are 1.74 Å. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(1), one O(2), and one O(7) atom. The Se(2)-O(1) bond length is 1.70 Å. The Se(2)-O(2) bond length is 1.74 Å. The Se(2)-O(7) bond length is 1.75 Å. In the third Se site, Se(3) is bonded in a trigonal non-coplanar geometry to one O(4) and two equivalent O(6) atoms. The Se(3)-O(4) bond length is 1.82 Å. Both Se(3)-O(6) bond lengths are 1.70 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to two equivalent Ba(1) and one Se(2) atom. In the second O site, O(2) is bonded in a 4-coordinate geometry to two equivalent Ba(1), one Cu(1), and one Se(2) atom. In the third O site, O(3) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Cu(1), and one Se(1) atom. In the fourth O site, O(4) is bonded in a trigonal planar geometry to two equivalent Cu(1) and one Se(3) atom. In the fifth O site, O(5) is bonded in a 3-coordinate geometry to two equivalent Ba(1) and one Se(1) atom. In the sixth O site, O(6) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Cu(1), and one Se(3) atom. In the seventh O site, O(7) is bonded in a 2-coordinate geometry to two equivalent Ba(1), one Cu(1), and one Se(2) atom.