CeSe2 crystallizes in the tetragonal P4/nmm space group. Ce(1) is bonded in a 9-coordinate geometry to four equivalent Se(2) and five equivalent Se(1) atoms. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to five equivalent Ce(1) atoms to form a mixture of distorted corner and edge-sharing SeCe5 trigonal bipyramids. In the second Se site, Se(2) is bonded in a 8-coordinate geometry to four equivalent Ce(1) and four equivalent Se(2) atoms.
CeSe2 crystallizes in the tetragonal P4/nmm space group. Ce(1) is bonded in a 9-coordinate geometry to four equivalent Se(2) and five equivalent Se(1) atoms. All Ce(1)-Se(2) bond lengths are 3.13 Å. There is one shorter (3.07 Å) and four longer (3.08 Å) Ce(1)-Se(1) bond lengths. There are two inequivalent Se sites. In the first Se site, Se(1) is bonded to five equivalent Ce(1) atoms to form a mixture of distorted corner and edge-sharing SeCe5 trigonal bipyramids. In the second Se site, Se(2) is bonded in a 8-coordinate geometry to four equivalent Ce(1) and four equivalent Se(2) atoms. All Se(2)-Se(2) bond lengths are 2.98 Å.