CuSe is Covellite structured and crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Se(1) and three equivalent Se(2) atoms to form distorted CuSe4 tetrahedra that share corners with three equivalent Se(2)Cu3Se tetrahedra and corners with seven equivalent Cu(1)Se4 tetrahedra. In the second Cu site, Cu(2) is bonded in a trigonal planar geometry to three equivalent Se(1) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted pentagonal planar geometry to two equivalent Cu(1) and three equivalent Cu(2) atoms. In the second Se site, Se(2) is bonded to three equivalent Cu(1) and one Se(2) atom to form distorted SeCu3Se tetrahedra that share corners with three equivalent Cu(1)Se4 tetrahedra and corners with six equivalent Se(2)Cu3Se tetrahedra.
CuSe is Covellite structured and crystallizes in the orthorhombic Cmcm space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded to one Se(1) and three equivalent Se(2) atoms to form distorted CuSe4 tetrahedra that share corners with three equivalent Se(2)Cu3Se tetrahedra and corners with seven equivalent Cu(1)Se4 tetrahedra. The Cu(1)-Se(1) bond length is 2.47 Å. There are two shorter (2.39 Å) and one longer (2.46 Å) Cu(1)-Se(2) bond length. In the second Cu site, Cu(2) is bonded in a trigonal planar geometry to three equivalent Se(1) atoms. There is one shorter (2.28 Å) and two longer (2.31 Å) Cu(2)-Se(1) bond lengths. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded in a distorted pentagonal planar geometry to two equivalent Cu(1) and three equivalent Cu(2) atoms. In the second Se site, Se(2) is bonded to three equivalent Cu(1) and one Se(2) atom to form distorted SeCu3Se tetrahedra that share corners with three equivalent Cu(1)Se4 tetrahedra and corners with six equivalent Se(2)Cu3Se tetrahedra. The Se(2)-Se(2) bond length is 2.40 Å.