CuO crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a linear geometry to one O(1) and one O(2) atom. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to two equivalent O(1) and three equivalent O(2) atoms. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Cu(1) and two equivalent Cu(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Cu(1) and three equivalent Cu(2) atoms.
CuO crystallizes in the orthorhombic Pnma space group. There are two inequivalent Cu sites. In the first Cu site, Cu(1) is bonded in a linear geometry to one O(1) and one O(2) atom. The Cu(1)-O(1) bond length is 1.82 Å. The Cu(1)-O(2) bond length is 1.82 Å. In the second Cu site, Cu(2) is bonded in a 5-coordinate geometry to two equivalent O(1) and three equivalent O(2) atoms. Both Cu(2)-O(1) bond lengths are 1.88 Å. There are two shorter (1.90 Å) and one longer (2.56 Å) Cu(2)-O(2) bond length. There are two inequivalent O sites. In the first O site, O(1) is bonded in a distorted trigonal non-coplanar geometry to one Cu(1) and two equivalent Cu(2) atoms. In the second O site, O(2) is bonded in a 4-coordinate geometry to one Cu(1) and three equivalent Cu(2) atoms.