CeSe2 crystallizes in the monoclinic C2 space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form corner-sharing CeSe4 tetrahedra. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(2) atom. In the second Se site, Se(2) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. In the third Se site, Se(3) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(2) atom. In the fourth Se site, Se(4) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom.
CeSe2 crystallizes in the monoclinic C2 space group. There are two inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form corner-sharing CeSe4 tetrahedra. The Ce(1)-Se(1) bond length is 2.73 Å. The Ce(1)-Se(2) bond length is 2.72 Å. The Ce(1)-Se(3) bond length is 2.73 Å. The Ce(1)-Se(4) bond length is 2.74 Å. In the second Ce site, Ce(2) is bonded to one Se(1), one Se(2), one Se(3), and one Se(4) atom to form corner-sharing CeSe4 tetrahedra. The Ce(2)-Se(1) bond length is 2.73 Å. The Ce(2)-Se(2) bond length is 2.74 Å. The Ce(2)-Se(3) bond length is 2.73 Å. The Ce(2)-Se(4) bond length is 2.73 Å. There are four inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(2) atom. In the second Se site, Se(2) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. In the third Se site, Se(3) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(2) atom. In the fourth Se site, Se(4) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom.