Materials Data on CsSmHgSe3 by Materials Project

Abstract

CsSmHgSe3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Cs1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Cs–Se bond distances ranging from 3.72–3.92 Å. Sm3+ is bonded to six Se2- atoms to form SmSe6 octahedra that share corners with two equivalent SmSe6 octahedra, edges with two equivalent SmSe6 octahedra, and edges with four equivalent HgSe4 tetrahedra. The corner-sharing octahedral tilt angles are 39°. There are four shorter (2.98 Å) and two longer (3.00 Å) Sm–Se bond lengths. Hg2+ is bonded to four Se2- atoms to form HgSe4 tetrahedra that share corners with two equivalent HgSe4 tetrahedra and edges with four equivalent SmSe6 octahedra. There are two shorter (2.64 Å) and two longer (2.78 Å) Hg–Se bond lengths. There are two inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 6-coordinate geometry to two equivalent Cs1+, two equivalent Sm3+, and two equivalent Hg2+ atoms. In the second Se2- site, Se2- is bonded in a 6-coordinate geometry to three equivalent Cs1+, two equivalent Sm3+, and one Hg2+ atom.