CeSe2 is Low Tridymite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(6), one Se(7), and two equivalent Se(2) atoms to form corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(6), one Se(7), and two equivalent Se(1) atoms to form corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to one Se(1), one Se(3), and two equivalent Se(4) atoms to form corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one Se(2), one Se(3), and two equivalent Se(5) atoms to form corner-sharing CeSe4 tetrahedra. There are seven inequivalent Se sites. In the first Se site, Se(3) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(4) atom. In the second Se site, Se(4) is bonded in a bent 150 degrees geometry to two equivalent Ce(3) atoms. In the third Se site, Se(5) is bonded in a bent 150 degrees geometry to two equivalent Ce(4) atoms. In the fourth Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. In the fifth Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. In the sixth Se site, Se(1) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the seventh Se site, Se(2) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(4) atom.
CeSe2 is Low Tridymite-like structured and crystallizes in the orthorhombic Cmc2_1 space group. There are four inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(6), one Se(7), and two equivalent Se(2) atoms to form corner-sharing CeSe4 tetrahedra. The Ce(1)-Se(6) bond length is 2.73 Å. The Ce(1)-Se(7) bond length is 2.73 Å. Both Ce(1)-Se(2) bond lengths are 2.73 Å. In the second Ce site, Ce(2) is bonded to one Se(6), one Se(7), and two equivalent Se(1) atoms to form corner-sharing CeSe4 tetrahedra. The Ce(2)-Se(6) bond length is 2.73 Å. The Ce(2)-Se(7) bond length is 2.73 Å. Both Ce(2)-Se(1) bond lengths are 2.73 Å. In the third Ce site, Ce(3) is bonded to one Se(1), one Se(3), and two equivalent Se(4) atoms to form corner-sharing CeSe4 tetrahedra. The Ce(3)-Se(1) bond length is 2.72 Å. The Ce(3)-Se(3) bond length is 2.73 Å. Both Ce(3)-Se(4) bond lengths are 2.73 Å. In the fourth Ce site, Ce(4) is bonded to one Se(2), one Se(3), and two equivalent Se(5) atoms to form corner-sharing CeSe4 tetrahedra. The Ce(4)-Se(2) bond length is 2.72 Å. The Ce(4)-Se(3) bond length is 2.73 Å. There is one shorter (2.72 Å) and one longer (2.73 Å) Ce(4)-Se(5) bond length. There are seven inequivalent Se sites. In the first Se site, Se(3) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(4) atom. In the second Se site, Se(4) is bonded in a bent 150 degrees geometry to two equivalent Ce(3) atoms. In the third Se site, Se(5) is bonded in a bent 150 degrees geometry to two equivalent Ce(4) atoms. In the fourth Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. In the fifth Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. In the sixth Se site, Se(1) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(3) atom. In the seventh Se site, Se(2) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(4) atom.