Cu4Se3O10 crystallizes in the triclinic P-1 space group. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(10), one O(2), one O(6), and two equivalent O(1) atoms to form a mixture of distorted edge and corner-sharing CuO5 trigonal bipyramids. In the second Cu site, Cu(2) is bonded to one O(2), one O(4), one O(5), one O(6), and one O(9) atom to form a mixture of edge and corner-sharing CuO5 trigonal bipyramids. In the third Cu site, Cu(3) is bonded to one O(1), one O(4), one O(5), and two equivalent O(8) atoms to form a mixture of distorted edge and corner-sharing CuO5 square pyramids. In the fourth Cu site, Cu(4) is bonded to one O(1), one O(10), one O(7), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing CuO5 trigonal bipyramids. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(2), one O(3), and one O(4) atom. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(5), one O(6), and one O(7) atom. In the third Se site, Se(3) is bonded in a distorted trigonal non-coplanar geometry to one O(10), one O(8), and one O(9) atom. There are ten inequivalent O sites. In the first O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one Cu(1), one Cu(4), and one Se(3) atom. In the second O site, O(1) is bonded to one Cu(3), one Cu(4), and two equivalent Cu(1) atoms to form edge-sharing OCu4 tetrahedra. In the third O site, O(2) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one Se(1) atom. In the fourth O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Cu(4) and one Se(1) atom. In the fifth O site, O(4) is bonded in a trigonal planar geometry to one Cu(2), one Cu(3), and one Se(1) atom. In the sixth O site, O(5) is bonded in a trigonal planar geometry to one Cu(2), one Cu(3), and one Se(2) atom. In the seventh O site, O(6) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one Se(2) atom. In the eighth O site, O(7) is bonded in a bent 120 degrees geometry to one Cu(4) and one Se(2) atom. In the ninth O site, O(8) is bonded in a trigonal planar geometry to two equivalent Cu(3) and one Se(3) atom. In the tenth O site, O(9) is bonded in a bent 120 degrees geometry to one Cu(2) and one Se(3) atom.
Cu4Se3O10 crystallizes in the triclinic P-1 space group. There are four inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one O(10), one O(2), one O(6), and two equivalent O(1) atoms to form a mixture of distorted edge and corner-sharing CuO5 trigonal bipyramids. The Cu(1)-O(10) bond length is 2.36 Å. The Cu(1)-O(2) bond length is 1.97 Å. The Cu(1)-O(6) bond length is 1.98 Å. There is one shorter (1.91 Å) and one longer (1.98 Å) Cu(1)-O(1) bond length. In the second Cu site, Cu(2) is bonded to one O(2), one O(4), one O(5), one O(6), and one O(9) atom to form a mixture of edge and corner-sharing CuO5 trigonal bipyramids. The Cu(2)-O(2) bond length is 2.01 Å. The Cu(2)-O(4) bond length is 1.98 Å. The Cu(2)-O(5) bond length is 2.27 Å. The Cu(2)-O(6) bond length is 1.95 Å. The Cu(2)-O(9) bond length is 1.92 Å. In the third Cu site, Cu(3) is bonded to one O(1), one O(4), one O(5), and two equivalent O(8) atoms to form a mixture of distorted edge and corner-sharing CuO5 square pyramids. The Cu(3)-O(1) bond length is 1.93 Å. The Cu(3)-O(4) bond length is 2.03 Å. The Cu(3)-O(5) bond length is 2.00 Å. There is one shorter (1.96 Å) and one longer (2.25 Å) Cu(3)-O(8) bond length. In the fourth Cu site, Cu(4) is bonded to one O(1), one O(10), one O(7), and two equivalent O(3) atoms to form a mixture of distorted edge and corner-sharing CuO5 trigonal bipyramids. The Cu(4)-O(1) bond length is 1.92 Å. The Cu(4)-O(10) bond length is 1.98 Å. The Cu(4)-O(7) bond length is 1.96 Å. There is one shorter (1.96 Å) and one longer (2.33 Å) Cu(4)-O(3) bond length. There are three inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted trigonal non-coplanar geometry to one O(2), one O(3), and one O(4) atom. The Se(1)-O(2) bond length is 1.73 Å. The Se(1)-O(3) bond length is 1.70 Å. The Se(1)-O(4) bond length is 1.74 Å. In the second Se site, Se(2) is bonded in a trigonal non-coplanar geometry to one O(5), one O(6), and one O(7) atom. The Se(2)-O(5) bond length is 1.71 Å. The Se(2)-O(6) bond length is 1.76 Å. The Se(2)-O(7) bond length is 1.68 Å. In the third Se site, Se(3) is bonded in a distorted trigonal non-coplanar geometry to one O(10), one O(8), and one O(9) atom. The Se(3)-O(10) bond length is 1.70 Å. The Se(3)-O(8) bond length is 1.71 Å. The Se(3)-O(9) bond length is 1.73 Å. There are ten inequivalent O sites. In the first O site, O(10) is bonded in a distorted trigonal non-coplanar geometry to one Cu(1), one Cu(4), and one Se(3) atom. In the second O site, O(1) is bonded to one Cu(3), one Cu(4), and two equivalent Cu(1) atoms to form edge-sharing OCu4 tetrahedra. In the third O site, O(2) is bonded in a distorted trigonal planar geometry to one Cu(1), one Cu(2), and one Se(1) atom. In the fourth O site, O(3) is bonded in a distorted trigonal planar geometry to two equivalent Cu(4) and one Se(1) atom. In the fifth O site, O(4) is bonded in a trigonal planar geometry to one Cu(2), one Cu(3), and one Se(1) atom. In the sixth O site, O(5) is bonded in a trigonal planar geometry to one Cu(2), one Cu(3), and one Se(2) atom. In the seventh O site, O(6) is bonded in a trigonal planar geometry to one Cu(1), one Cu(2), and one Se(2) atom. In the eighth O site, O(7) is bonded in a bent 120 degrees geometry to one Cu(4) and one Se(2) atom. In the ninth O site, O(8) is bonded in a trigonal planar geometry to two equivalent Cu(3) and one Se(3) atom. In the tenth O site, O(9) is bonded in a bent 120 degrees geometry to one Cu(2) and one Se(3) atom.