CeSe2 is quartz (alpha)-like structured and crystallizes in the triclinic P-1 space group. There are eight inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(1), one Se(10), one Se(13), and one Se(5) atom to form corner-sharing CeSe4 tetrahedra. In the second Ce site, Ce(2) is bonded to one Se(13), one Se(2), one Se(6), and one Se(9) atom to form corner-sharing CeSe4 tetrahedra. In the third Ce site, Ce(3) is bonded to one Se(12), one Se(14), one Se(3), and one Se(7) atom to form corner-sharing CeSe4 tetrahedra. In the fourth Ce site, Ce(4) is bonded to one Se(11), one Se(14), one Se(4), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. In the fifth Ce site, Ce(5) is bonded to one Se(15), one Se(4), one Se(7), and one Se(9) atom to form corner-sharing CeSe4 tetrahedra. In the sixth Ce site, Ce(6) is bonded to one Se(10), one Se(16), one Se(3), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. In the seventh Ce site, Ce(7) is bonded to one Se(11), one Se(15), one Se(2), and one Se(5) atom to form corner-sharing CeSe4 tetrahedra. In the eighth Ce site, Ce(8) is bonded to one Se(1), one Se(12), one Se(16), and one Se(6) atom to form corner-sharing CeSe4 tetrahedra. There are sixteen inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(8) atom. In the second Se site, Se(2) is bonded in a distorted bent 150 degrees geometry to one Ce(2) and one Ce(7) atom. In the third Se site, Se(3) is bonded in a distorted bent 150 degrees geometry to one Ce(3) and one Ce(6) atom. In the fourth Se site, Se(4) is bonded in a bent 150 degrees geometry to one Ce(4) and one Ce(5) atom. In the fifth Se site, Se(5) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(7) atom. In the sixth Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(8) atom. In the seventh Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(5) atom. In the eighth Se site, Se(8) is bonded in a bent 150 degrees geometry to one Ce(4) and one Ce(6) atom. In the ninth Se site, Se(9) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(5) atom. In the tenth Se site, Se(10) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(6) atom. In the eleventh Se site, Se(11) is bonded in a bent 150 degrees geometry to one Ce(4) and one Ce(7) atom. In the twelfth Se site, Se(12) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(8) atom. In the thirteenth Se site, Se(13) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. In the fourteenth Se site, Se(14) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(4) atom. In the fifteenth Se site, Se(15) is bonded in a bent 150 degrees geometry to one Ce(5) and one Ce(7) atom. In the sixteenth Se site, Se(16) is bonded in a bent 150 degrees geometry to one Ce(6) and one Ce(8) atom.
CeSe2 is quartz (alpha)-like structured and crystallizes in the triclinic P-1 space group. There are eight inequivalent Ce sites. In the first Ce site, Ce(1) is bonded to one Se(1), one Se(10), one Se(13), and one Se(5) atom to form corner-sharing CeSe4 tetrahedra. The Ce(1)-Se(1) bond length is 2.73 Å. The Ce(1)-Se(10) bond length is 2.73 Å. The Ce(1)-Se(13) bond length is 2.74 Å. The Ce(1)-Se(5) bond length is 2.74 Å. In the second Ce site, Ce(2) is bonded to one Se(13), one Se(2), one Se(6), and one Se(9) atom to form corner-sharing CeSe4 tetrahedra. The Ce(2)-Se(13) bond length is 2.73 Å. The Ce(2)-Se(2) bond length is 2.74 Å. The Ce(2)-Se(6) bond length is 2.73 Å. The Ce(2)-Se(9) bond length is 2.74 Å. In the third Ce site, Ce(3) is bonded to one Se(12), one Se(14), one Se(3), and one Se(7) atom to form corner-sharing CeSe4 tetrahedra. The Ce(3)-Se(12) bond length is 2.74 Å. The Ce(3)-Se(14) bond length is 2.73 Å. The Ce(3)-Se(3) bond length is 2.74 Å. The Ce(3)-Se(7) bond length is 2.73 Å. In the fourth Ce site, Ce(4) is bonded to one Se(11), one Se(14), one Se(4), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. The Ce(4)-Se(11) bond length is 2.73 Å. The Ce(4)-Se(14) bond length is 2.74 Å. The Ce(4)-Se(4) bond length is 2.73 Å. The Ce(4)-Se(8) bond length is 2.74 Å. In the fifth Ce site, Ce(5) is bonded to one Se(15), one Se(4), one Se(7), and one Se(9) atom to form corner-sharing CeSe4 tetrahedra. The Ce(5)-Se(15) bond length is 2.74 Å. The Ce(5)-Se(4) bond length is 2.73 Å. The Ce(5)-Se(7) bond length is 2.74 Å. The Ce(5)-Se(9) bond length is 2.74 Å. In the sixth Ce site, Ce(6) is bonded to one Se(10), one Se(16), one Se(3), and one Se(8) atom to form corner-sharing CeSe4 tetrahedra. The Ce(6)-Se(10) bond length is 2.73 Å. The Ce(6)-Se(16) bond length is 2.74 Å. The Ce(6)-Se(3) bond length is 2.74 Å. The Ce(6)-Se(8) bond length is 2.73 Å. In the seventh Ce site, Ce(7) is bonded to one Se(11), one Se(15), one Se(2), and one Se(5) atom to form corner-sharing CeSe4 tetrahedra. The Ce(7)-Se(11) bond length is 2.73 Å. The Ce(7)-Se(15) bond length is 2.73 Å. The Ce(7)-Se(2) bond length is 2.74 Å. The Ce(7)-Se(5) bond length is 2.74 Å. In the eighth Ce site, Ce(8) is bonded to one Se(1), one Se(12), one Se(16), and one Se(6) atom to form corner-sharing CeSe4 tetrahedra. The Ce(8)-Se(1) bond length is 2.73 Å. The Ce(8)-Se(12) bond length is 2.74 Å. The Ce(8)-Se(16) bond length is 2.73 Å. The Ce(8)-Se(6) bond length is 2.73 Å. There are sixteen inequivalent Se sites. In the first Se site, Se(1) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(8) atom. In the second Se site, Se(2) is bonded in a distorted bent 150 degrees geometry to one Ce(2) and one Ce(7) atom. In the third Se site, Se(3) is bonded in a distorted bent 150 degrees geometry to one Ce(3) and one Ce(6) atom. In the fourth Se site, Se(4) is bonded in a bent 150 degrees geometry to one Ce(4) and one Ce(5) atom. In the fifth Se site, Se(5) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(7) atom. In the sixth Se site, Se(6) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(8) atom. In the seventh Se site, Se(7) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(5) atom. In the eighth Se site, Se(8) is bonded in a bent 150 degrees geometry to one Ce(4) and one Ce(6) atom. In the ninth Se site, Se(9) is bonded in a bent 150 degrees geometry to one Ce(2) and one Ce(5) atom. In the tenth Se site, Se(10) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(6) atom. In the eleventh Se site, Se(11) is bonded in a bent 150 degrees geometry to one Ce(4) and one Ce(7) atom. In the twelfth Se site, Se(12) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(8) atom. In the thirteenth Se site, Se(13) is bonded in a bent 150 degrees geometry to one Ce(1) and one Ce(2) atom. In the fourteenth Se site, Se(14) is bonded in a bent 150 degrees geometry to one Ce(3) and one Ce(4) atom. In the fifteenth Se site, Se(15) is bonded in a bent 150 degrees geometry to one Ce(5) and one Ce(7) atom. In the sixteenth Se site, Se(16) is bonded in a bent 150 degrees geometry to one Ce(6) and one Ce(8) atom.