CeSe2 crystallizes in the triclinic P1 space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(1), one Se(3), one Se(5), and one Se(6) atom to form corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(2), one Se(6), one Se(7), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to one Se(3), one Se(4), one Se(5), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one Se(1), one Se(2), one Se(4), and one Se(7) atom to form corner-sharing CeSe4 tetrahedra. There are eight 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(4) atom. In the second Se site, Se(2) is bonded in a bent 120 degrees geometry to one Ce(2) and one Ce(4) 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(3) and one Ce(4) atom. In the fifth Se site, Se(5) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(3) atom. In the sixth Se site, Se(6) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(2) atom. In the seventh Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(4) atom. In the eighth Se site, Se(8) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom.
CeSe2 crystallizes in the triclinic P1 space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(1), one Se(3), one Se(5), and one Se(6) atom to form corner-sharing CeSe4 tetrahedra. The Ce(1)-Se(1) bond length is 2.71 Å. The Ce(1)-Se(3) bond length is 2.71 Å. The Ce(1)-Se(5) bond length is 2.72 Å. The Ce(1)-Se(6) bond length is 2.72 Å. In the second Ce site, Ce(2) is bonded to one Se(2), one Se(6), one Se(7), 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(6) bond length is 2.71 Å. The Ce(2)-Se(7) bond length is 2.72 Å. The Ce(2)-Se(8) bond length is 2.70 Å. In the third Ce site, Ce(3) is bonded to one Se(3), one Se(4), one Se(5), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. The Ce(3)-Se(3) bond length is 2.71 Å. The Ce(3)-Se(4) bond length is 2.70 Å. The Ce(3)-Se(5) bond length is 2.72 Å. The Ce(3)-Se(8) bond length is 2.72 Å. In the fourth Ce site, Ce(4) is bonded to one Se(1), one Se(2), one Se(4), and one Se(7) atom to form corner-sharing CeSe4 tetrahedra. The Ce(4)-Se(1) bond length is 2.71 Å. The Ce(4)-Se(2) bond length is 2.72 Å. The Ce(4)-Se(4) bond length is 2.70 Å. The Ce(4)-Se(7) bond length is 2.72 Å. There are eight 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(4) atom. In the second Se site, Se(2) is bonded in a bent 120 degrees geometry to one Ce(2) and one Ce(4) 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(3) and one Ce(4) atom. In the fifth Se site, Se(5) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(3) atom. In the sixth Se site, Se(6) is bonded in a bent 120 degrees geometry to one Ce(1) and one Ce(2) atom. In the seventh Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(4) atom. In the eighth Se site, Se(8) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom.