CeSe2 crystallizes in the tetragonal I4/m 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(3), one Se(4), and two equivalent Se(5) atoms to form corner-sharing CeSe4 tetrahedra. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 120 degrees geometry to two equivalent Ce(1) atoms. In the second Se site, Se(2) is bonded in a linear geometry to two equivalent Ce(1) atoms. 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 120 degrees geometry to one Ce(1) and one Ce(2) atom. In the fifth Se site, Se(5) is bonded in a bent 120 degrees geometry to two equivalent Ce(2) atoms.
CeSe2 crystallizes in the tetragonal I4/m 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 2.73 Å. In the second Ce site, Ce(2) is bonded to one Se(3), one Se(4), and two equivalent Se(5) atoms to form corner-sharing CeSe4 tetrahedra. The Ce(2)-Se(3) bond length is 2.72 Å. The Ce(2)-Se(4) bond length is 2.72 Å. Both Ce(2)-Se(5) bond lengths are 2.73 Å. There are five inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 120 degrees geometry to two equivalent Ce(1) atoms. In the second Se site, Se(2) is bonded in a linear geometry to two equivalent Ce(1) atoms. 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 120 degrees geometry to one Ce(1) and one Ce(2) atom. In the fifth Se site, Se(5) is bonded in a bent 120 degrees geometry to two equivalent Ce(2) atoms.