Li2Cu3(Se2O7)2 crystallizes in the monoclinic C2/c space group. Li(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form LiO4 tetrahedra that share corners with three equivalent Cu(1)O5 square pyramids and corners with two equivalent Se(2)O4 tetrahedra. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form distorted CuO5 square pyramids that share corners with two equivalent Se(2)O4 tetrahedra and corners with three equivalent Li(1)O4 tetrahedra. In the second Cu site, Cu(2) is bonded in a distorted square co-planar geometry to two equivalent O(1) and two equivalent O(7) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted T-shaped geometry to one O(5), one O(6), and one O(7) atom. In the second Se site, Se(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SeO4 tetrahedra that share corners with two equivalent Cu(1)O5 square pyramids and corners with two equivalent Li(1)O4 tetrahedra. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cu(2) and one Se(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Cu(1) and one Se(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Cu(1), and one Se(2) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Li(1) and one Se(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Cu(1), and one Se(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Cu(1), and one Se(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one Se(1) atom.
Li2Cu3(Se2O7)2 crystallizes in the monoclinic C2/c space group. Li(1) is bonded to one O(3), one O(4), one O(5), and one O(6) atom to form LiO4 tetrahedra that share corners with three equivalent Cu(1)O5 square pyramids and corners with two equivalent Se(2)O4 tetrahedra. The Li(1)-O(3) bond length is 2.04 Å. The Li(1)-O(4) bond length is 2.07 Å. The Li(1)-O(5) bond length is 2.04 Å. The Li(1)-O(6) bond length is 2.03 Å. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(2), one O(3), one O(5), one O(6), and one O(7) atom to form distorted CuO5 square pyramids that share corners with two equivalent Se(2)O4 tetrahedra and corners with three equivalent Li(1)O4 tetrahedra. The Cu(1)-O(2) bond length is 1.96 Å. The Cu(1)-O(3) bond length is 2.41 Å. The Cu(1)-O(5) bond length is 1.98 Å. The Cu(1)-O(6) bond length is 1.98 Å. The Cu(1)-O(7) bond length is 1.98 Å. In the second Cu site, Cu(2) is bonded in a distorted square co-planar geometry to two equivalent O(1) and two equivalent O(7) atoms. Both Cu(2)-O(1) bond lengths are 2.02 Å. Both Cu(2)-O(7) bond lengths are 1.91 Å. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted T-shaped geometry to one O(5), one O(6), and one O(7) atom. The Se(1)-O(5) bond length is 1.73 Å. The Se(1)-O(6) bond length is 1.73 Å. The Se(1)-O(7) bond length is 1.80 Å. In the second Se site, Se(2) is bonded to one O(1), one O(2), one O(3), and one O(4) atom to form SeO4 tetrahedra that share corners with two equivalent Cu(1)O5 square pyramids and corners with two equivalent Li(1)O4 tetrahedra. The Se(2)-O(1) bond length is 1.71 Å. The Se(2)-O(2) bond length is 1.70 Å. The Se(2)-O(3) bond length is 1.66 Å. The Se(2)-O(4) bond length is 1.67 Å. There are seven inequivalent O sites. In the first O site, O(1) is bonded in a bent 120 degrees geometry to one Cu(2) and one Se(2) atom. In the second O site, O(2) is bonded in a bent 120 degrees geometry to one Cu(1) and one Se(2) atom. In the third O site, O(3) is bonded in a distorted trigonal non-coplanar geometry to one Li(1), one Cu(1), and one Se(2) atom. In the fourth O site, O(4) is bonded in a bent 120 degrees geometry to one Li(1) and one Se(2) atom. In the fifth O site, O(5) is bonded in a distorted trigonal planar geometry to one Li(1), one Cu(1), and one Se(1) atom. In the sixth O site, O(6) is bonded in a trigonal planar geometry to one Li(1), one Cu(1), and one Se(1) atom. In the seventh O site, O(7) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one Se(1) atom.