K2Cu3(SeO3)4 crystallizes in the triclinic P-1 space group. K(1) is bonded in a 7-coordinate geometry to one O(5), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(6) atom. In the second Cu site, Cu(2) is bonded in an octahedral geometry to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one O(2), one O(4), and one O(6) atom. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(1), one O(3), and one O(5) atom. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent K(1), one Cu(1), and one Se(2) atom to form distorted edge-sharing OK2CuSe tetrahedra. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Cu(1), one Cu(2), and one Se(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent K(1), one Cu(1), and one Se(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent K(1) and one Se(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one K(1), one Cu(2), and one Se(2) atom. In the sixth O site, O(6) is bonded in a trigonal non-coplanar geometry to one Cu(1), one Cu(2), and one Se(1) atom.
K2Cu3(SeO3)4 crystallizes in the triclinic P-1 space group. K(1) is bonded in a 7-coordinate geometry to one O(5), two equivalent O(1), two equivalent O(3), and two equivalent O(4) atoms. The K(1)-O(5) bond length is 3.01 Å. Both K(1)-O(1) bond lengths are 2.91 Å. There is one shorter (2.79 Å) and one longer (3.03 Å) K(1)-O(3) bond length. There is one shorter (2.80 Å) and one longer (2.89 Å) K(1)-O(4) bond length. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a rectangular see-saw-like geometry to one O(1), one O(2), one O(3), and one O(6) atom. The Cu(1)-O(1) bond length is 1.94 Å. The Cu(1)-O(2) bond length is 1.96 Å. The Cu(1)-O(3) bond length is 1.97 Å. The Cu(1)-O(6) bond length is 2.01 Å. In the second Cu site, Cu(2) is bonded in an octahedral geometry to two equivalent O(2), two equivalent O(5), and two equivalent O(6) atoms. Both Cu(2)-O(2) bond lengths are 2.44 Å. Both Cu(2)-O(5) bond lengths are 2.00 Å. Both Cu(2)-O(6) bond lengths are 2.03 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a trigonal non-coplanar geometry to one O(2), one O(4), and one O(6) atom. The Se(1)-O(2) bond length is 1.76 Å. The Se(1)-O(4) bond length is 1.67 Å. The Se(1)-O(6) bond length is 1.82 Å. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(1), one O(3), and one O(5) atom. The Se(2)-O(1) bond length is 1.74 Å. The Se(2)-O(3) bond length is 1.73 Å. The Se(2)-O(5) bond length is 1.74 Å. There are six inequivalent O sites. In the first O site, O(1) is bonded to two equivalent K(1), one Cu(1), and one Se(2) atom to form distorted edge-sharing OK2CuSe tetrahedra. In the second O site, O(2) is bonded in a distorted trigonal non-coplanar geometry to one Cu(1), one Cu(2), and one Se(1) atom. In the third O site, O(3) is bonded in a 4-coordinate geometry to two equivalent K(1), one Cu(1), and one Se(2) atom. In the fourth O site, O(4) is bonded in a 3-coordinate geometry to two equivalent K(1) and one Se(1) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one K(1), one Cu(2), and one Se(2) atom. In the sixth O site, O(6) is bonded in a trigonal non-coplanar geometry to one Cu(1), one Cu(2), and one Se(1) atom.