CeSe2 crystallizes in the orthorhombic C222 space group. There are six 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(2), one Se(5), one Se(6), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to two equivalent Se(3) and two equivalent Se(7) atoms to form corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to two equivalent Se(4) and two equivalent Se(7) atoms to form corner-sharing CeSe4 tetrahedra. In the fifth Ce site, Ce(5) is bonded to two equivalent Se(6) and two equivalent Se(9) atoms to form corner-sharing CeSe4 tetrahedra. In the sixth Ce site, Ce(6) is bonded to two equivalent Se(5) and two equivalent Se(9) atoms to form corner-sharing CeSe4 tetrahedra. There are nine inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 150 degrees geometry to two equivalent Ce(1) atoms. In the second Se site, Se(2) is bonded in a linear 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(3) atom. In the fourth Se site, Se(4) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(4) atom. In the fifth Se site, Se(5) is bonded in a bent 120 degrees geometry to one Ce(2) and one Ce(6) atom. In the sixth Se site, Se(6) is bonded in a bent 120 degrees geometry to one Ce(2) and one Ce(5) atom. In the seventh Se site, Se(7) is bonded in a bent 120 degrees geometry to one Ce(3) and one Ce(4) atom. In the eighth Se site, Se(8) is bonded in a bent 150 degrees geometry to two equivalent Ce(2) atoms. In the ninth Se site, Se(9) is bonded in a bent 120 degrees geometry to one Ce(5) and one Ce(6) atom.
CeSe2 crystallizes in the orthorhombic C222 space group. There are six 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 2.71 Å. The Ce(1)-Se(4) bond length is 2.72 Å. In the second Ce site, Ce(2) is bonded to one Se(2), one Se(5), one Se(6), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. The Ce(2)-Se(2) bond length is 2.71 Å. The Ce(2)-Se(5) bond length is 2.73 Å. The Ce(2)-Se(6) bond length is 2.72 Å. The Ce(2)-Se(8) bond length is 2.74 Å. In the third Ce site, Ce(3) is bonded to two equivalent Se(3) and two equivalent Se(7) atoms to form corner-sharing CeSe4 tetrahedra. Both Ce(3)-Se(3) bond lengths are 2.72 Å. Both Ce(3)-Se(7) bond lengths are 2.71 Å. In the fourth Ce site, Ce(4) is bonded to two equivalent Se(4) and two equivalent Se(7) atoms to form corner-sharing CeSe4 tetrahedra. Both Ce(4)-Se(4) bond lengths are 2.73 Å. Both Ce(4)-Se(7) bond lengths are 2.71 Å. In the fifth Ce site, Ce(5) is bonded to two equivalent Se(6) and two equivalent Se(9) atoms to form corner-sharing CeSe4 tetrahedra. Both Ce(5)-Se(6) bond lengths are 2.73 Å. Both Ce(5)-Se(9) bond lengths are 2.72 Å. In the sixth Ce site, Ce(6) is bonded to two equivalent Se(5) and two equivalent Se(9) atoms to form corner-sharing CeSe4 tetrahedra. Both Ce(6)-Se(5) bond lengths are 2.72 Å. Both Ce(6)-Se(9) bond lengths are 2.72 Å. There are nine inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 150 degrees geometry to two equivalent Ce(1) atoms. In the second Se site, Se(2) is bonded in a linear 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(3) atom. In the fourth Se site, Se(4) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(4) atom. In the fifth Se site, Se(5) is bonded in a bent 120 degrees geometry to one Ce(2) and one Ce(6) atom. In the sixth Se site, Se(6) is bonded in a bent 120 degrees geometry to one Ce(2) and one Ce(5) atom. In the seventh Se site, Se(7) is bonded in a bent 120 degrees geometry to one Ce(3) and one Ce(4) atom. In the eighth Se site, Se(8) is bonded in a bent 150 degrees geometry to two equivalent Ce(2) atoms. In the ninth Se site, Se(9) is bonded in a bent 120 degrees geometry to one Ce(5) and one Ce(6) atom.