Materials Data on CeSe2 by Materials Project

Abstract

CeSe2 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent Ce4+ sites. In the first Ce4+ site, Ce4+ is bonded to six Se2- atoms to form distorted CeSe6 octahedra that share corners with two CeSe5 trigonal bipyramids, edges with three CeSe5 trigonal bipyramids, and an edgeedge with one CeSe4 trigonal pyramid. There are a spread of Ce–Se bond distances ranging from 2.76–2.96 Å. In the second Ce4+ site, Ce4+ is bonded to five Se2- atoms to form CeSe5 trigonal bipyramids that share a cornercorner with one CeSe6 octahedra, corners with two equivalent CeSe5 trigonal bipyramids, corners with two equivalent CeSe4 trigonal pyramids, and an edgeedge with one CeSe6 octahedra. The corner-sharing octahedral tilt angles are 53°. There are a spread of Ce–Se bond distances ranging from 2.72–2.88 Å. In the third Ce4+ site, Ce4+ is bonded to four Se2- atoms to form CeSe4 trigonal pyramids that share corners with four CeSe5 trigonal bipyramids and an edgeedge with one CeSe6 octahedra. There are a spread of Ce–Se bond distances ranging from 2.69–2.79 Å. In the fourth Ce4+ site, Ce4+ is bonded to five Se2- atoms to form CeSe5 trigonal bipyramids that share a cornercorner with one CeSe6 octahedra, corners with two equivalent CeSe5 trigonal bipyramids, corners with two equivalent CeSe4 trigonal pyramids, and edges with two equivalent CeSe6 octahedra. The corner-sharing octahedral tilt angles are 36°. There are a spread of Ce–Se bond distances ranging from 2.69–2.89 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a bent 120 degrees geometry to two Ce4+ atoms. In the second Se2- site, Se2- is bonded in a bent 120 degrees geometry to two Ce4+ atoms. In the third Se2- site, Se2- is bonded in a distorted T-shaped geometry to three Ce4+ atoms. In the fourth Se2- site, Se2- is bonded in a bent 120 degrees geometry to two Ce4+ atoms. In the fifth Se2- site, Se2- is bonded in a bent 150 degrees geometry to two Ce4+ atoms. In the sixth Se2- site, Se2- is bonded in a distorted T-shaped geometry to three Ce4+ atoms. In the seventh Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to three Ce4+ atoms. In the eighth Se2- site, Se2- is bonded in a T-shaped geometry to three Ce4+ atoms.